A Church of England bishop has issued a statement alleging he was subjected to a “violent” beating by the head of a Christian charity accused of sadomasochistic attacks on young boys.

Andrew Watson, the Bishop of Guildford, said he was the victim of a “violent, excruciating and shocking” beating in a garden shed during the 1970s or 1980s.

It follows a Channel 4 News report containing allegations that John Smyth QC used holiday camps to groom teenagers, who he forced to strip naked before beating them.

Archbishop of Canterbury Justin Welby was forced to issue an "unreserved and unequivocal" apology on behalf of the church after admitting he had worked at the holiday camps.

Archbishop of Canterbury Justin Welby (Getty)

Mr Watson described the abuser as” misguided, manipulative and dangerous”.

He said he had contacted Hampshire Police, which is already conducting an investigation into similar claims made against Mr Smyth.

The statement posted on the Diocese of Guildford’s website said: “I am one of the survivors of John Smyth’s appalling activities in the late 1970s and early ‘80s.

“I am also one of the Bishops in the Church of England.

“This has placed me in a unique and challenging position when it comes to the events of the past few days.

“My own story is certainly less traumatic than that of some others. I was drawn into the Smyth circle, as they were, and the beating I endured in the infamous garden shed was violent, excruciating and shocking; but it was thankfully a one-off experience never to be repeated.

“A while later one of my friends attempted suicide on the eve of another session in the shed (a story movingly told in the Channel 4 Report), and at that point I and a friend shared our story.”

One alleged victim told Channel 4 he and other boys were beaten so violently they had to wear nappies to stop the bleeding.

"We recognise that many institutions fail catastrophically, but the Church is meant to hold itself to a far, far higher standard and we have failed terribly," a statement on behalf of the Archbishop said.

"For that the Archbishop apologises unequivocally and unreservedly to all survivors.”

The Archbishop said he became friends with Mr Smyth in the late 1970s, when Mr Welby was a dormitory officer and Mr Smyth was one of the main leaders at the Iwerne holiday camps.

Lambeth Palace said they had since exchanged “the occasional card”.