A CROWBAR used in the Great Train Robbery went up for sale at Amersham Auction House today, fetching £550.

The two metre long steel rod was used to pry open carriage doors as part of the 1963 theft which netted £2.6 million.

This was the largest robbery in British history until 2006, when it was superseded by the £53 million Securitas depot robbery in Kent.

The bar was bought by a pair of mystery bidders at the auction house in Station Road who entered the room in the middle of the auction and left before the end.

Hugo Lemon, one of the auction house directors, said: "We're very happy.

"It was a very unusual item but they do tend to turn up at the auction house.

"Another item I have coming up is Lady Diana's bicycle.

"That's what makes auctioneering so interesting - you never know what's going to turn up."

The bar has been in the possession of a former memorabilia shop owner William Kirby for 42 years.

In 1966 the police, who were trying to clear out the evidence following the robbers' trial, brought the bar into Mr Kirby's shop, The Collectors Corner, next to Euston Station, London.

Mr Kirby was unable to sell the historic oddity, and when he closed down his shop moved it to his garage in Rickmansworth where it languished until the auction.

Thirteen members of the gang that robbed the London to Glasgow travelling post office were eventually caught.

The £2.6 million taken during the robbery would be valued at around £40 million today.

Most of the sum, which was made up of £1, £5 and £10 notes, was never recovered.