Ronnie Biggs was sentenced to 30 years in jail
Great Train robber Ronnie Biggs has been taken to hospital after falling ill in prison.
Biggs was moved to the Norfolk and Norwich University Hospital in Norwich from nearby Norwich Prison, his son Michael Biggs has confirmed to the BBC.
The 79-year-old is thought to be suffering from pneumonia.
Michael Biggs said he was told about his father's illness by a journalist and said: "I'll be travelling up from London to see him tomorrow."
He added: "Why is my father still in prison? He's costing the tax payer thousands. He's been in prison for 10 years now and he is no danger to society."
The Ministry of Justice said it did not comment on individual cases.
Biggs was jailed for 30 years for his part in the 1963 robbery but escaped and went on the run. He returned in 2001 to serve the rest of his sentence.
Biggs has been in poor health after suffering a series of strokes and heart attacks.
His son has long campaigned for his father to be released on compassionate grounds.
Biggs was transferred on compassionate grounds from the high security Belmarsh prison, in south-east London, in June 2007.
The unit at Norwich Prison is specially designed for elderly inmates on life sentences.
Biggs had served only 15 months of his 30-year-sentence when he escaped from Wandsworth Prison.
He was on the run for 35 years after fleeing to Paris and Australia, then Brazil.