Ronnie Biggs now regrets the act which he committed 48 years ago.
In an interview given to the ITV on the eve of the launch of his new autobiography, the Great Train Robber said he was sorry for what happened to mail train driver Jack Mills, who died in 1970 having never made a full recovery after being coshed.
Biggs. 82, has been suffering from ill health since his release in 2009. He finds it difficult to walk or talk as a result of a stroke that he suffered early this year.
He was part of a gang that made off with £2.6 million from a Glasgow -London mail train in 1963.
His autobiography, Odd Man Out: The Last Straw, is due to be launched in London on Thursday.
The new book is an update on his 1994 autobiography. Biggs will talk about his later years including his return to the UK, his jail term and his release from jail.
Biggs, 82, from Lambeth, south London, had a suspected stroke in February at a nursing home in Barnet, north London. He first suffered a stroke in 1998 and has been admitted to hospital several times since returning to the UK.
Biggs was handed a 30-year sentence but managed to escape from Wandsworth prison, south London, in a furniture van after spending 15 months in jail. He was on the run for more than three decades, living in Spain, Australia and Brazil before returning to the UK voluntarily.