A CHILD killer and rapist suspected over the unsolved disappearance of a Northern Ireland schoolgirl has died in prison in County Durham.

Robert Howard was last seen with Arlene Arkinson, from Castlederg, Co Tyrone, before she vanished after a night out at a disco across the Irish border in Co Donegal in August 1994.

Eleven years later, Howard was acquitted of her murder.

The trial jury was unaware of his history of sex attacks and his conviction for strangling south London teenager Hannah Williams in 2001.

The 71-year-old was in jail in Frankland Prison, Durham, and was due to give evidence at the re-ordered inquest into Arlene's death in Belfast.

Howard is believed to have died from natural causes.

A spokesman for the Prison Service division of the UK's Ministry of Justice said: "HMP Frankland prisoner Robert Howard was pronounced dead in hospital at 1.55pm on Friday.

"As with all deaths in custody there will be an investigation by the independent Prisons and Probation Ombudsman."

Despite 92 searches and a long-running missing persons investigation, Arlene's body has never been recovered.

The inquest into her death has been beset with many delays, including officers from the Police Service of Northern Ireland (PSNI) security-vetting 70 case files ahead of the hearings.

It had been due to run at the start of September, almost eight years after the first preliminary hearing was held, but that depended on the PSNI completing disclosure of the case files by July 10.

Arlene's sister Kathleen has vowed to never give up the fight to uncover what happened.