Photos of Lord Lucan are an exact match for a British pensioner living in Australia, a world-renowned facial recognition expert has claimed.

Richard John Bingham, 7th Earl of Lucan, fled after murdering his nanny Sandra Rivett in his London home 48 years ago tomorrow, with numerous rumours about what happened next centred around Kent – including one in which his body was eaten by tigers at Howletts.

Now, leading computer scientist Professor Hassan Ugai – who identified the Russian men behind the novichok attack on the Skripals in Salisbury – has told The Mirror he has definitively matched photos of an OAP living near Brisbane with ones of Lucan.

"That is not opinion it is scientific and mathematical fact," he told the paper in a world exclusive.

A reporter from The Mirror approached the British pensioner in his home.

He reportedly became "stressed" and told his carers to tell the reporter "I'm not Lord Lucan." But the pensioner, who is a practising Buddhist, has apparently told others he used to live in Belgravia and knows royalty.

The man was initially tracked down by Mr Rivett's son nine years ago, before Prof Ugai got involved.

Prof Ugai told the paper: “Even if you put two images of the same person you never get 100% similarity.

“Anything with a similarity index of 75% or higher is conclusively the same individual. The lowest score I got was around 76. I think the highest was 88.”

He says his software has been used to compare millions of photos and has "never been wrong".

On Friday, it was revealed three Cluedo cards were found in Lucan's car: the lead pipe, Colonel Mustard and the hall.

There were various theories as to what happened to him after he fled his Belgravia home.

His car was discovered in East Sussex with a bloodied lead pipe in the boot and friends believed he jumped off a cross-Channel ferry soon after.

Others think he escaped in a plane which took off from Headcorn aerodrome, while perhaps the most famous theory is Lucan, then 39, was fed to a tiger at his friend John Aspinall's Howletts zoo, near Canterbury.

Read more: The mystery of Lord Lucan

That startling account came from Phillippe Marcq, who says he was trusted with the true story behind the peer’s disappearance in 1974.

Mr Marcq was a former stockbroker who used to play backgammon with Lucan at the exclusive Clermont Club in London, which was also owned by Mr Aspinall.

Speaking from his home in Wiltshire in 2016 he says he was standing in the corner of the club when fellow stockbroker Stephen Raphael told him what had happened to Lucan.

Lord Lucan was declared legally dead the same year.