Ian Michael Buck was found hanging from a knotted blanket on Friday morning by his cellmate. His death will increase pressure from probation officers, prison reformers and Labour MPs on Michael Howard, the Home Secretary, to bring private prisons under stricter public control.
Mr Buck was sent to Doncaster after receiving a three year sentence two weeks ago for threatening to kill and possessing an imitation firearm with intent to kidnap.
The prison is run by Premier Prisons, a consortium formed between Wackenhut, a Florida-based private security corporation, and Serco, a services company. Premier Prisons was awarded an pounds 11m-a-year contract to manage the jail by the Prison Service. The contract was part of Mr Howard's plans to privatise 10 per cent of prisons - a policy which he said would raise standards and improve efficiency.
But since the jail opened three months ago, there have been accusations of prisoners bullying and stealing from weaker inmates, several protests by prisoners, and an escape from the jail the offenders have nicknamed 'Doncatraz'.
Rosemary Wool, the Government's director of prison health services, has criticised the standards of medical care. Probation officers and lawyers have complained of lengthy delays before seeing clients.
Stephen Nathan, a spokesman for the Prison Reform Trust, called yesterday for the jail to be put under public control.
'The Government cannot go on saying these are teething problems,' he said. ''The ideological privatisation programme needs to come to an end.'
Last week, the Trust, a pressure group which represents prisoners, received a letter from an inmate at Doncaster. 'People like me are getting smacked every day,' he wrote. The prisoner, whose name is not being released by the Trust, said that his requests to be moved to the prison hospital had been ignored, and alleged staff failed to stop the assaults on him from other inmates. 'I'm thinking of doing myself in rather than letting them do it for me,' he said.
A consortium spokesman said attempts to revive Mr Buck had failed and the police were investigating.
An internal investigation began at Dartmoor jail yesterday after a prisoner was found hanged in his cell.
Paul Jones, 31, from South Wales who arrived at the Devon jail on Thursday, was serving a nine month sentence for drug offences, imposed at Cardiff Crown Court on September 9, a prison spokesman said.
He was last seen at 8pm on Friday night and discovered hanging 15 minutes later. Attempts by prison officers to revive Jones failed.