POLICE HAVE been called in to investigate the suspected murder of a prisoner who was found hanging by a ligature in a jail toilet.

Lancashire detectives were yesterday interviewing prisoners and staff at Garth prison, near Preston, Lancashire, where the body of convicted murderer Kevin McCarthy was discovered early on Monday. The death was initially treated as suicide but information was passed to the police leading them to believe that the death was "suspicious".

The Prison Service said last night that it had initiated its own inquiry and had sent in a governor from a separate prison to conduct an independent investigation. McCarthy's mental condition had been giving cause for concern and he was placed under "suicide watch" in the prison's health care centre.

McCarthy had served seven years of a life sentence for murder after being convicted at St Albans crown court in 1991.

Stephen Shaw, director of the Prison Reform Trust, said such deaths were difficult to investigate because of a prisoners' code of silence.