Former teacher Sion Jenkins said today he contemplated suicide during his darkest moments while accused of murdering his teenage foster daughter.

Only the thought of how his death would cause suffering to his four daughters prevented him from taking his own life in the wake of 13-year-old Billie-Jo Jenkins' killing.

Billie-Jo was found in a pool of blood with head injuries inflicted by a metal tent peg on the patio of the family's Victorian home in Lower Park Road, Hastings.

Mr Jenkins, at the time headteacher-designate at all-boys William Parker School in Hastings, was convicted but later cleared of murder following three trials and two appeals.

He maintained his innocence throughout the protracted legal process and insisted Billie-Jo must have been killed by an intruder while he was at a DIY store on February 15, 1997.

Speaking on Radio 4's On The Ropes, Mr Jenkins said he felt close to "crumbling" at Belmarsh prison following his conviction at Lewes Crown Court in 1998.

He said: "I knew I had to be robust in order to get through but when I was convicted and went to Belmarsh I had a very difficult few days when I first went there.

"When I was dumped in one particular cell, I had people staring through the cell door at me and leering and the quadrant all around me. I had hundreds of prisoners shouting abuse and saying what there were going to do to me when on the wing.

"And when eventually I did go on the wing on my third day, I went for a bath and three men came in and tried to drown me.

"After that incident when I felt totally wretched, I felt very alone and I felt that I was crumbling, it was at that point that I think I reached my lowest point."

Mr Jenkins said he reached a point where he vowed never to give up fighting to clear his name, saying it was important for the sake of Billie-Jo, his other daughters, Annie, Charlotte, Esther and Maya, and his family.

He said: "I knew that if I simply gave way and folded, if I took my own life it would be Annie, Charlotte, Esther and Maya that would suffer. I did think of that, yes."

There were claims by his ex-wife Lois Jenkins that she and their daughters suffered domestic violence at his hands, allegations flatly rejected by him.

He also denied a witness's claim at trial that he lashed out at Billie-Jo during a family holiday, and said he felt it almost impossible to defend himself when allegations were made about him.

He said: "Lois has said many things. I think Lois was persuaded of my guilt and started speaking about things that were not true."

Mr Jenkins, who now lives in Lymington, Hampshire, with second wife Christina Ferneyhough, spoke of his relief at being formally acquitted following his third trial last year.

He said he sat "comfortably" with the thought other people may still think him guilty despite walking free.

He said: "When I stepped out I gave thanks to God and I rejoiced that I would be going home. When I went back in (to court) and the judge gave the instructions that not guilty should be put on the indictment and that I would be walking out, I did rejoice at that moment.

"I knew that I was going home and that not guilty was going to be put on the indictment and that's what I felt at that moment, that I had received justice."

He added: "It was the Crown's responsibility to persuade the jury of my guilt and they could not do that."

Mr Jenkins called for the metal tent peg used to bludgeon Billie-Jo to be subjected to modern DNA techniques.

And he said he was writing a book but denied he was making money from the case, insisting reports he was in line to receive a £500,000 compensation payout were untrue.

Following the killing, his ex-wife emigrated to Australia with their four daughters, a moment he described as another lowest point.

He said: "The book is primarily for my daughters. I haven't been able to speak to them, to say why our family was torn in two.

"And it is in a sense a letter for my daughters so they can understand what has happened to me and what has happened to us."