It is said if you have bought gold jewellery in the UK since November 1983 the chances are you were wearing some of the £26 million worth of the bullion stolen during the Brink's-Mat robbery.

Such was the scale of the theft, it was described at the time as the "crime of the century" - a haul which dwarfed all crimes before it and made the £2.6m proceeds of the Great Train Robbery look like chump change.

And its reach would extend into Kent where key figures lived, gold and vast quantities of cash were smuggled and lives would be taken.

Interest in the crime is set to pique once again as the BBC prepares to unleash The Gold, a star-studded six-part dramatisation of the events surrounding the heist.

What it will not be able to solve is perhaps the greatest mystery of all...just where is half the gold - stolen on that fateful day - today? It has never been recovered. There is no money trail. It could, just could, be hidden somewhere in Kent.

Unknown to Anthony 'Tony' Black, when he got a job as a security guard on an industrial estate in Heathrow in 1979, it would start a chain of events which would lead him into a life of infamy and extraordinary danger.

After serving in the Army, a failed marriage had seen him return to living with his parents in Bromley, but salvation was at hand when he got a job guarding the Brink's-Mat warehouse - a nondescript secure unit used to store vast quantities of cash and valuable metals. Including gold.

Security was tight. There was CCTV, advanced deadlocks and always a team of security guards.

As he settled into life he looked for somewhere of his own to live. His elder sister, Jennifer, revealed her partner, Brian Robinson, had a flat available. He leapt at the opportunity and, in doing so, put himself in the debt of the man who would become the criminal mastermind behind the raid.

Robinson was aware of the regular sums of money passing through the Brink's-Mat warehouse - up to £2m on occasion - and knew his brother-in-law gave him, quite literally, a foot in the door.

Known as 'The Colonel', Robinson had a long history of armed robberies and was well known to the police.

Over time, he cultivated Black, eventually letting him in on the scheme and introducing him to his partner-in-crime Micky McAvoy. The two seasoned criminals hatched a plan.

Using information provided by Black and using him to allow them to gain access, they planned to force their way into the warehouse at 6.30am on November 26, 1983.

When Black turned up for work, he unlocked a side door and signalled to a group of men waiting in a blue transit van outside.

Within moments, six armed men, wearing balaclavas, entered the warehouse. They were ruthless to the guards, caught by surprise, knocking several out. Using Black's inside knowledge they identified those who held the keys and codes to the vault within the unit.

They threatened them - dousing them in petrol; telling them they knew where their families lived. Black was not attacked but ordered by the gang to open the doors.

But there was a problem. One of the guards, in the panic he felt during the raid, couldn't remember his code. The gang lit a match as they contemplated the raid leaving them empty-handed - knives were held to the guards' throats.

They wanted the cash in the main safe. But as the guard struggled to remember his access code, they stumbled upon something far more valuable. Gold. Crates and crates of gold bars, or ingots. All stamped with the magic numbers of 9999 - meaning it was 99.99% pure gold.

They had hit a jackpot they didn't even realise was there.

In total there was almost three tonnes of gold - almost 7,000 bars of the purest, most valuable metal. Suddenly, the code to the cash vault didn't seem so important.

Such was the quantity they stole, the getaway van was visibly weighed down. It creaked under the weight of, what was then, £26.5m worth of gold. Today the figure would be closer to £100m.

By the time the guards were able to call the police, the crooks had disappeared.

The gold was owned by Johnson Matthey Bankers which handled gold bullion and used the Brink's-Mat warehouse to transfer its valuable cargo between banks or overseas. The gold it had that fateful day was due to be escorted to Gatwick Airport for onward shipment to the likes of Hong Kong.

Such was the impact of the crime on the price of gold, the haul they made off with increased in value by £1m within 24 hours.

Of course, stealing such a vast quantity of gold is one thing. Turning it into cash amid a media and public frenzy in the aftermath of such a raid, quite something else.

Especially when a £2m reward was swiftly put up for information leading to its return.

The police and government knew that the impact of such a vast quantity of cash flowing into the underworld could spell trouble further down the road. Finding it and the crooks became priority number one.

But police knew they faced a race against time. With each gold bar bearing the crest and serial number of Johnson Matthey, to extract the value meant liquifying the gold. It would have to be smelted down to disguise it. In other words, melted down and recast.

The police quickly realised that the gang's ability to access the site pointed to an inside job. Black quickly came to their attention. Eight days after the crime he was arrested.

His hopes of financial security disappearing, he blabbed.

Robinson and McAvoy were arrested on Black's evidence days later. When Black was asked to identify McAvoy in an identity parade, McAvoy expressed his displeasure by punching him hard in the face.

Robinson insisted he had an alibi. He told police he was visiting his mother on Sheppey - stopping off at a Little Chef on the M2 en route. The police didn't buy it and the three were all charged.

Black was rewarded for his efforts with a price on his head. The underworld chattered to claims that the death of the former security guard carried a £50,000 bounty.

When he appeared in court in February, he was jailed for six years.

Later that year McAvoy and Robinson all faced trial at the Old Bailey amid tight security. During the hearing one of the security guards attacked during the raid saw threats made to his mother in Sheerness and girlfriend in Gravesend. He was immediately given around the clock police protection.

Robinson and McAvoy were both found guilty and sentenced to 25 years, without parole.

But despite the breakthrough, the police were still left with the small matter of the gold - neither hide nor hair of which had been seen since the robbery.

What they did not know was that McAvoy had agreed that were they to be caught, an old friend, Brian Perry, was to take control of their share of the gold and safeguard it until their release.

Perry, however, had other plans.

With his old mates behind bars and unlikely to emerge any time soon, he set about turning some of the gold into hard cash.

He got in touch with Kenneth Noye.

Noye was both a successful businessman and member of the criminal underworld. He lived in a plush mock-tudor house in leafy West Kingsdown. To assist him, he called in old mate Brian Reader to assist.

Unfortunately for Noye, he quickly came on the police radar when officers tracked a smelting machine being bought under suspicious circumstances and taken to Noye's home.

He was put under surveillance. On one occasion he travelled - and was tailed - to Jersey where he paid, in cash, for 11 solid gold bars - a gift he said, for his son. What it gave Noye was a receipt for the legitimate ownership of gold bars. Handy for what he was about to get involved in.

Being careful to only ever handle 11 bars at a time, the gang transported the gold from its hiding place - which has never been found - through Noye and smelter John Palmer (they mixed it with copper coins to disguise its purity and, most importantly, source) and up to a gold bullion company in Bristol called Scadlynn.

There it was stamped legitimately and sold back on to the market.

Ironically, one of the biggest buyers of the gold was Johnson Matthey Bankers - the very company it had been stolen from and which was now, unknowingly, buying it back. In total it bought back £13m worth.

In an era before there were such tight checks on the movement and withdrawal of huge sums of cash, people acting for Scadlynn withdrew hundreds of thousands of pounds at a time from its account - the proceeds of the now laundered Brink's-Mat gold - at a high street branch of Barclays nearby. It is thought some £14m went through its books during a one-year period following the raid.

In fact, the amounts demanded over the counter grew so large that the Bank of England had to make special arrangements to send cash to the bank. All freshly minted notes carried the AE24 prefix on the serial numbers. It would be key to linking money found as police closed in.

Meanwhile, back in Kent, police believed they were closing the net on Noye and Reader's activities.

On Saturday, January 26, 1985, officers called in two of their best surveillance experts to enter the grounds of Noye's home when they knew he was meeting Reader. They hoped to catch them in the act and secure the incriminating evidence they needed.

What occurred that night would haunt everyone involved forever more.

One of the two police undercover officers entering the gardens that night was 45-year-old John Fordham from Essex. He and his partner were dressed in camouflage and wearing balaclavas to avoid detection. Noye was known to take his security seriously - and had three pet Rottweilers who patrolled the grounds to act as an early warning system.

As the officers edged closer to the property - sneaking through its ground to get 'eyes on' what was going on inside, trouble erupted.

The dogs charged at them and started attacking them - barking to raise the alarm as they did so.

A figure with a torch was seen searching the grounds. Fordham's colleague saw two men approach where Fordham had been and heard raised voices and threats.

Police surged into the grounds of the property. They found Fordham with two men stood over him - one armed with a shotgun.

Noye and Reader fled. Paramedics arrived but Fordham died within moments of their arrival. He'd been stabbed 11 times in the chest, arms, back and head.

Reader ran through the grounds and out onto a main road where he thumbed a ride. Delighted when a car stopped, he was less so when he realised it was police and he was arrested.

Noye was arrested. Noye insisted immediately that Fordham had attacked him first and he had acted in self-defence.

Officers took the opportunity to search the property. During which they found 11 gold bars, crudely smelted.

Tested, they were the same purity as that of the Brink's-Mat gold. Large quantities of cash were also recovered - all with the tell-tale AE24 serial numbers.

A raid of Reader's home - he was then living in Lewisham - also unearthed large hauls of cash. Both were charged with Fordham's murder.

Police broadened their net and arrested a host of associates - including raiding John Palmer's house in Bath. Smelting gear was found but Palmer was 'on holiday' in Tenerife. It was a holiday he would be in no hurry to return from.

However, hopes of sending Noye and Reader down for Fordham's murder were premature. Both were found not guilty of murder on the grounds of self-defence.

Both were immediately re-arrested for their part in laundering the Brink's-Mat gold

When they finally appeared in court, in May 1986, they were both found guilty. Noye was sentenced to 13 years, Reader, described as Noye's 'right hand man' got nine.

As Noye heard the verdict he yelled at the jury: "I hope you all die of cancer".

Police, meanwhile, continued to pursue Palmer - nicknamed Goldfinger by the press - who was still 'on holiday'. Eventually, Spanish authorities deported him. Despite efforts to go elsewhere, as soon as he arrived back in the UK he was arrested. In the same month Noye and Reader were sent down, he was charged with 'conspiracy to dishonestly handle stolen bullion'.

At a trial the following spring he was, much to the police's frustration, acquitted.

He would, however, eventually be found guilty of a massive time-share scam in Spain and after being caught agreeing to launder drugs money on TV programme The Cook Report. He would be jailed for eight years.

Despite not finding any of the unadulterated gold bars, police were finally following the money made from the sale of the gold as it made its way through various off-shore and anonymous accounts in the likes of Switzerland and Liechtenstein.

Brian Perry, who had - much to the anger of mastermind McAvoy - taken control of his share of the gold, had now moved from Peckham to Biggin Hill. He'd also started a relationship with McAvoy's wife who he'd bought a large mansion for in Bickley, near Bromley. Just to make matters more complicated, he'd also bought McAvoy's mistress a house in the same village. A property she guarded with two dogs. Named Brinks and Mat.

The cops tracked down the solicitor involved in the purchase of the properties through off-shore accounts - Michael Relton. When he was arrested documents shed further light on the gold money's paper trail.

Relton, it transpired, had been informally appointed by Perry to build a financial empire with the gold. But not all it.

It is estimated around half of the gold remains either still hidden or smuggled out and smelted without the police's knowledge. It has never been recovered.

Much of the money laundered went into property in Kent and it was even invested in land in London's Docklands - once an abandoned industrial zone, now a highly prized, and hugely lucrative, property area. It is thought much of what stands there today was built on the bedrock of the proceeds of the stolen gold.

Eventually, Relton would be jailed for 12 years. Perry for nine.

But the story does not end there.

Kenneth Noye emerged from prison in 1994. He was also more than £3m poorer due to a civil action related to the Brink's-Mat robbery.

Just two years later, he became embroiled in another notorious case - the so-called 'road rage' murder of Dartford's Stephen Cameron, 21, on a slip-road of the M25 at Swanley.

Calling up his old mate John 'Goldfinger' Palmer for help, Palmer arranged for Noye to slip out of the country as the police investigation got under way.

He hid for a number of years in Spain before he was finally captured. He appeared in court in 2000. One of those giving evidence in the case was Alan Decabral. He too had a shady, underworld past. But he had witnessed the attack on the slip road and was key eye-witness testimony.

His evidence helped convict Noye who was jailed for 16 years.

Later that year, Decabral was shot dead in the car park of the Warren Retail Park in Ashford. No-one has ever been found guilty of the crime and it remains unsolved. It is not known the motive behind the killing.

Noye, however, was freed in 2019. He is now 75.

His former home in West Kingsdown - set off the road and with its own indoor swimming pool - was renamed and, when up for sale five years ago, commanded a £3m price-tag.

John Palmer was shot dead at his Essex home in 2015 at the age of 64. The case remains unsolved.

As for Brian Perry - the man who had assumed control of his old mates' share of their ill-gotten gains and even ran off with one of their wives?

He was shot dead by two masked men in November 2001 outside his minicab firm in Peckham just months after being released from jail. He was 63.

Coincidentally, McAvoy and Robinson had been released from jail the previous year.

Micky McAvoy died just a few weeks ago, on New Year's Eve. He was 70 and never got to profit from the raid which cost him 25 years of freedom.

Brian Robinson, who had lived in Beckenham following his release from jail, died in a nursing home in south London in early 2021. He was 77. He was said to be penniless. Friends still insisted he had not been involved in the raid itself.

Brian Reader clearly got a taste for a headline grabbing crime. He would later be the ringleader in the Hatton Garden raid of 2015 which netted some £14m from a vault containing safety deposit boxes.

He was arrested, at the age of 76, just weeks later. He was sentenced to six years and three months. He was released in 2018 after serving three years due to ill health. Now 82, it is believed he still lives in Dartford. He now suffers from dementia.

As for Tony Black - the security guard whose job started the cogs of the crooks' whirring? He, probably very wisely, went into hiding. His whereabouts unknown.

As for the money? Who knows...