OFFICIALS were last night investigating the death of a murderer who exchanged love letters with Soham killer Ian Huntley.

Louise Giles, 20, was serving a life sentence at HMP Durham, in Durham City, after she stabbed a woman to death with a kitchen knife in July last year.

She was discovered hanged in her cell at 11.34pm on Saturday.

Prison staff attempted to resuscitate her, but she was pronounced dead shortly after midnight, the Home Office revealed last night.

Her death is being investigated by the Prisons and Probation Ombudsman.

Durham has one of the worst records for suicides in the country and the Prison Service pledged last month to carry out an overhaul of the running of the jail.

Giles was 19 when she attacked 23-year-old Helen Hay with a kitchen knife in Sheffield.

Miss Hay was in a dispute with some other women outside a nightclub when Giles intervened, despite the fact that it had nothing to do with her.

She took the knife from her handbag and stabbed Miss Hay, a football centre assistant manager, seven times in the back and chest.

Giles was jailed for life at Sheffield Crown Court in May, with a minimum tariff of 14 years.

It has since emerged that she exchanged steamy notes with Huntley, 31, while she was on remand at his all-male top security prison.

Giles was sent to Wakefield Prison, where she spent three weeks, because it was the nearest high security jail to her trial in Sheffield.

A review of security was launched after it was revealed that she managed to smuggle notes to the double killer, despite guards watching him 24 hours a day on an isolation unit, where he was on suicide watch.

He sent back at least two letters before prison staff intercepted one.

Giles had her own team of female guards while at the prison and had been in the same health unit as Huntley, who is serving life for the murders of Holly Wells and Jessica Chapman, both ten.

Despite being heavily guarded, Giles, who was described as "totally crazy" during her trial, managed to beat the security cordon.

A Home Office spokesman confirmed Huntley's penpal had been found dead in Durham.

He said: "This was a traumatic incident for the staff and other prisoners. Our thoughts go out to Louise Giles' family at this difficult time."

Head of the Prison Service Niall Clifford admitted last month that significant improvements were needed at the prison.

His comments followed a report released by the Howard League for Penal Reform, which revealed 23 prisoners had taken their own lives there in the decade to March last year.

It was the third highest number in the country, behind Manchester and Leeds.

Fourteen of the deaths occurred in the final three years of the period.

Durham Coroner Andrew Tweddle has written twice to the Prison Service to highlight shortcomings in the handling of vulnerable prisoners following inquests into suicides dating back more than two years.

A performance improvement process is under way at the jail, which has 685 inmates