IT was one of the most notorious crimes of the 20th century. A gang of criminals robbed a Glasgow to London mail train in 1963 and got away with £2.6m - most of which was never traced.

Up until last year the Great Train Robbery was the biggest heist in English criminal history.

Today one of the £5 notes stolen from the train will be among a unique package of memorabilia going under the hammer at a Hampshire auction house.

The faded fiver belonged to Detective Sergeant Stan Davies, who bought it as a souvenir after arresting two of the gang members in Bournemouth.

He passed it on to his son, who has now decided to auction it off.

An old police notebook and photographs taken after the theft are also included in the lot, which is expected to fetch more than its estimated value of £120.

Edward Cowell, of George Kidner Auctioneers, said: "We've had a fair number of enquiries and are expecting a lot of interest."

Det Sgt Stan Davies was on duty in Bournemouth with a colleague when they received a tip-off from police widow Ethel Clark.

Her suspicion had been aroused by two men who wanted to rent her garage and offered to pay three months' rent up-front in used ten shilling notes.

The two detectives were waiting when the gang members showed up.

When the officers asked to look inside their van a violent struggle ensued before police reinforcements arrived and the robbers were arrested.

William Boal was jailed for 24 years and Roger Cordery for 20 years for their part in the robbery in Ledburn, Buckinghamshire.

Det Sgt Davies, who bought his souvenir note for £5 1s 9d, died in December 1991.

The cash stolen in the robbery would be worth about £40m in today's money, a sum eclipsed only by the £53m stolen in Securitas depot robbery in Tonbridge, Kent, last February.