A FORMER detective who murdered a policewoman from York was found dead in his prison cell after being moved from a high-observation unit, an inquest heard today.

Killer Peter Foster had been seen as a high suicide risk before being moved but a friend said his death was "inevitable" and said prison staff could not have prevented it.

Today's hearing at Eastbourne Town Hall was told Foster, 38, was "full of remorse" for murdering his partner Detective Constable Heather Cooper, from Acomb.

DC Cooper, 33, had two young children, Joshua and Isabel, but died in October 2011 when Foster hit her over the head ten times with a baseball bat then stabbed her in the throat at their home in Haslemere in Surrey, before dumping her body in a shallow grave in woods in West Sussex.

Friend Jonathon Carver, who is representing Foster's grandmother Marguerite Howkins at the inquest, told today's hearing that not being able to see his children after his arrest had a "profound affect" on Foster.

He said Foster had a difficult start in life, being abandoned by his mother and brought up by his grandmother, and said he was very hard on himself as a result.

He also had a difficult relationship with his father as he did not get on with his step-mother.

Mr Carver said Foster was prone to bouts of depression which became worse if he drank to excess.

He told the hearing Foster took the murder of his father in January 2009 badly and lost his job shortly afterwards when he committed a drink driving offence.

Foster, who retrained as a plumber, tried to take his own life in 2009 and was found close to death on his father's grave having taken pills and alcohol, Mr Carver said.

He said his friend had a faith and believed in life after death. The court also heard he had said to his grandmother while he was in prison: "The Foster men die young."

Mr Carver said: "We expected that Peter would die. For us it was a matter of when, not if."

He said Foster was "full of remorse" for what had happened and believed his friend had made his mind up about dying before he was sentenced, but that it may have pushed him over the edge.

He added: "We think that Peter's death was inevitable and that they (the prison staff) could not have stopped it.

"We believe the prison did what they could for him."

Foster was on the acute health care ward at Lewes Prison while on remand and was kept on the highest level of observation because he was deemed a high suicide risk.

But a month after he was jailed for life, and just days after his observations were relaxed to every hour, he was found dead.

Prison officer Geoff Gordon who worked on the ward described Foster as a pleasant and calm man who was interesting, vulnerable and bright.

He told the inquest that Foster was upstairs in the health care unit in a cell with a perspex door, where he could be constantly observed because he was seen as a high suicide risk.

He told the court that he was aware that Foster had tried to take his own life while on remand after getting hold of some pills.

But after he was sentenced he was moved downstairs where prisoners are not observed as frequently, the court heard.

Mr Gordon said the decision to relax Foster's regime did not lie with one person because "the burden would be too big if it went wrong".

Foster was jailed for life in June 2012 at Lewes Crown Court and told he must serve a minimum of 17 years. He was found dead on July 30.

Miss Cooper, a keen horse rider, trained at the Naburn Grange Riding Centre and later studied equestrian science at Bishop Burton College in East Yorkshire, before training to become a police officer. She joined Surrey Police in 2003 and had received a commendation in 2009.

Shortly before she died, she had talked about returning to York to be nearer her family, including parents James and Caroline Cooper.