by Ed McConnell and Annabel Rusbridge-Thomas

£53m of cash stolen. Seven men tried and convicted. 100 years total in sentences. And £32 million yet to be recovered.

This is the story of Britain's biggest heist - and the missing millions...

Ten years ago today the largest cash robbery in British history was taking place at a Tonbridge cash depot.

In the early hours of February 22, 2006, a Wednesday, seven masked men brandishing guns burst into Securitas Cash Management Ltd’s building in Vale Road, tied up 14 staff members and in just over an hour stole £53m belonging to the Bank of England.

The gang left almost £154m behind as they could not fit any more into their seven-and-a-half tonne lorry.

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Over the following years seven men were jailed for more than 100 years and £21m has been recovered.

The violent heist began the evening before when two men, dressed as police officers and wearing prosthetic masks, stopped depot manager Colin Dixon on the A249 near Stockbury. He was on his way home to Herne Bay.

He was taken by gun point to a remote farm where he was interrogated by the armed men.

VIDEO: Britain's biggest cash robbery - 10 years on

His wife and seven-year-old son were also kidnapped by other men posing as police and driven to the same location.

All three were taken to the depot around 1am in a convoy, which included the Renault lorry used to transport the cash back to the farm, and Mr Dixon was forced to reveal the security code.

Along with the depot’s employees, the family were bound and were left locked in cages. They only escaped when Mr Dixon’s young son squeezed through the bars and freed them.

In the weeks following the raid arrests were made, vehicles were seized and hordes of cash discovered.

First a Parcelforce van, linked to the abduction of the Dixons, who have since been given new identities, was found at the Hook and Hatchet pub in Hucking.

Then two cars, disguised to look like undercover police vehicles, were found in Leeds and Mr Dixon’s Nissan was discovered at the Cock Horse pub in Detling.

A horde of £8m was found in a lock-up in Southborough.

A white transit van containing £1.3m, guns, body armour and balaclavas was found in an Ashford car park. The haul was linked to now convicted robbers Lea Rush and Jetmir Bucpapa.

Metal cages used to transport the £53m were recovered from a field near Detling.

By early March Kent Police revealed they had found almost £20m and by summer said they had made 30 arrests over the course of an investigation, which by the end of the year would have cost £6m.

The remaining £32m taken that February night has not been found.

The largest cash robbery ever not only had a profound and lasting effect on the 14 members of staff and three members of the Dixon family but also on the company targeted.

Without a £53m heist, the Securitas depot at Tonbridge would have been unknown to most Kent residents. It was holding cash for the Bank of England when the robbers struck.

In the months after the crime the company changed beyond all recognition.

The firm, based in Stockholm, which once operated a large fleet of armoured vans across the country, no longer deals in cash handling or management. Instead its areas of expertise are security, technology and consulting.

While the Vale Road depot still exists, it is now under the banner of Vaultex, a company owned by Barclays and HSBC.

Its cash handling arm has been transferred to Loomis.

It's a change which, while planned for some time, was rushed through in the wake of the heist.

What exactly has happened to the £32m still missing is the biggest mystery of all. Whether it was shipped off to some far flung corner of the globe, meticulously laundered or buried somewhere is a question on the lips of all those tangled up in the complex web of criminality.

The loss has long since been covered by the company’s insurers, who continue to work closely with the police to track down the cash.

Ascot, a Lloyd’s syndicate that leads the dozens of insurers involved, has now appointed specialist lawyers Clyde & Co to join the hunt for the missing millions.

A total of £3.5m of confiscation orders has been served against five of the robbers currently in prison, which can be increased if suspicious financial goings on take place at a later date.

Efforts to repatriate assets from Morocco, where Allen and Murray were caught and imprisoned, continue.

"Finding a needle in a hay stack would be an easier job."

That’s the opinion of former detective superintendent Nick Biddiss who thinks the missing £32m is long gone.

He said the money would certainly have been taken out of the country after the heist and would have long since disappeared into the murky world of international criminal finance.

But, he added, the robbers wouldn’t have had an easy time of it, with crooks waiting to rip them off at every opportunity.

He said: “Criminals will want to come along and get a bit of the action by taking massive cuts, it’s almost like insurance, that’s the kind of life these people live. You can’t go to the police if you’re being exploited because you’ve committed a crime.”

"The money from Securitas is long gone" - Nick Biddiss

With electronic transfers and online deals becoming standard practice in the last decade, he said laundering such a large sum would have become much simpler than when he served on the force 18 years ago.

While £32m might seem like a lot, Mr Biddiss says it would be easy to blow through these unconventional channels and added he didn’t think the money would last a lifetime.

Explaining just how far the ill-gotten gains may have been distributed, Mr Biddiss said: “After Brink’s-Mat, people said every bit of jewellery you bought post 1985 would have a bit of the gold in it. The money from Securitas is long gone.”

Those convicted

Lee Murray: A cagefighter aged 27 at the time from south London. Fled to Morocco soon after the robbery and was jailed there for 25 years.

Believed to have masterminded the operation.

Paul Allen: Then 28, from Chatham, also fled to Morocco but was extradited back and handed an 18-year sentence.

Has just been released after serving six years of and three on remand, qualifying him for release on licence.

Lea Rusha: Was 35, of Lambersart Close, Southborough. Linked to two locations where almost £10m was was discovered.

Disguises and plans found at his home and played central part in robbery. Indefinite sentence - minimum 15 years.

Stuart Royle: Then 59, Allen Street, Maidstone. Court heard probably one of robbers, potentially a kidnapper.

Indefinite sentence, minimum 15 years.

Roger Coutts: Then 30, of south London. Strong links to Lee Murray, linked to locations where more than £18m found and DNA on cable ties used to bind staff.

Indefinite sentence - minimum 15 years.

Emir Hysenaj: Then aged 28, from East Sussex. The inside man employed at Securitas depot. 20-year jail term.

Jetmir Bucpapa: Was 26, of Hadlow Road near the depot, linked to £1.4m stash, liased with Hysenaj. After appeal sentence replaced with 30 year term.

In 2010, Ian Bowrem, then 47 and from Devon, jailed for three years and nine months after almost £1m found in the boot of his car. £380,000 was linked to the robbery.

Those cleared

John Fowler: Acquitted. A car dealer, then aged 60, owned Elderden Farm in Staplehurst, which the prosecution alleged provided a base for robbers and where the Dixon family held. Mr Fowler always denied this. He was accused of hiring the lorry but jury unanimously found he was innocent and had been manipulated by Stuart Royle.

Keith Borer: lived in Little Venice, Yalding, also cleared. He had been accused of handling money and changing the identity of a van used in the kidnapping.

Michelle Hogg, then 33 and of south London, began 2007 trial as a defendant accused of disguising the kidnappers with facecasts, but became key prosecution witness.

Michael Demetris, of Bromley, Michelle Hogg’s boss, cleared of making disguises. He said he had no idea they were to be used for crime, but thought they were for a video game.

Royle’s girlfriend Kim Shackleton, of Allen Street, Maidstone; Bucpapa’s girlfriend Raluca Millen, of Dudley Road, Tunbridge Wells and Rusha’s girlfriend Katie Philp, of Hadlow Road, Tonbridge, were cleared of their involvement in the crimes in 2008.

Amateur boxing coach Sean Lupton, of Herne Bay, is still at large and is believed to be hiding in northern Cyprus after vanishing while on bail.