THE youngest detective to join the hunt for the Great Train Robbers has spoken of his “mixed feelings” at the decision to release Ronnie Biggs.

The 79-year-old robber, who is seriously ill with pneumonia, was formally released from prison on Friday by justice minister Jack Straw, weeks after he ruled Biggs should serve the rest of his sentence.

Ken Rogers, a Wivenhoe town councillor and former Flying Squad detective, had written to Mr Straw calling for Biggs to be freed on compassionate grounds, but was keen to emphasise the deterrent affect of prison sentences.

“Biggs is not really being set free because he’s going to spend the rest of his few weeks of life in hospital,” he said.

“When someone is as seriously ill as he is, releasing them is the right thing to do. If he was fit and well I would say he should serve his full sentence, however old he is.

“We have to show the criminal that crime doesn’t pay.”

Mr Rogers was part of the elite squad of detectives sent after the robbers, who made off with £2.6million after stopping a mail train as it passed through Buckinghamshire, in August 1963.

Train driver Jack Mills suffered serious head injuries after being hit in the raid.

Mr Rogers, who is Wivenhoe’s community safety and neighbourhood watch co-ordinator and researches crime and security issues, said: “It was an exciting case to work on, because we were dealing with professional, vicious criminals.

“We were working long days with very little sleep, trying to trace them and watching various places we knew they frequented.”

Police quickly tracked the gang down and Mr Rogers finally came face-to-face with the crooks when they appeared in court the following year.

As they were sentenced, Mr Rogers’ boss, Det Chief Insp Tommy Butler, made a startling prediction.

“We were sitting close to the dock and he said to me ‘Look at them very closely because they are going over the wall’. And they did,” he said.

“I will never forget those words, it was absolutely amazing he had the inkling that was going to happen.”

Biggs, who was a getaway driver, was given a 30-year jail sentence, but escaped from Wandsworth prison after only 15 months by climbing over the wall and hiding in a furniture van.

On the run he became a cult figure, living in Australia and Brazil, before coming back to Britain in 2001.

He was immediately sent back to prison, but was taken to hospital from Norwich prison in June this year after falling ill.

Mr Rogers defended Biggs’ imprisonment into old age as punishment for the “diabolical” attack on Mr Mills.

“People forget that when a person is attacked like that, it affects them for the rest of their life and Mr Mills never really got over it,” he said.

“Biggs was sitting in a vehicle so he was not involved in the violence directly, but he has to accept his responsibility for it.

“He was part of the violence through the planning, execution and aftermath of the raid.”