Radical Muslim gangs are imposing a form of sharia law inside some of Britain's prisons, a BBC investigation has found.

According to one former prison officer, younger prisoners are particularly targeted for forced conversion to Islam by these gangs.

The officer believes that they go along out of fear and intimidation.

He says that one Catholic prisoner who refused to convert was seriously assaulted after being repeatedly threatened by the gang.

The officer's testimony is consistent with findings by the official prison watchdog, the chief inspector of prisons.

In a report last year, the inspector, Anne Owers, quoted a number of prisoners at Long Lartin about the increasing dominance of Muslim gangs in the jail.

According to The Telegraph, two Muslim former prisoners claimed in the BBC programme that Muslims "run" some London jails and describe how they watched al-Qaeda videos in their cells, brought in by corrupt prison officers.

They also detail further bullying and abuse of prisoners who refused to convert to Islam and said that in one London jail, prisoners who wanted to play music had their stereos smashed. They said that the official prison imams appointed by the Home Office were largely ineffective and not respected by Muslim prisoners.

A spokesman for the Ministry of Justice said: "It is ridiculous to suggest that any gang 'controls' a prison. The spokesman also said there was "no evidence" that al-Qaeda videos had been watched and insisted that bacon was not banned. (ANI)