Convicted police killer Dale Cregan has been moved to a maximum-security psychiatric hospital after refusing food for a month.

Cregan, 30, has been transferred to Ashworth, the same secure hospital where Moors Murderer Ian Brady is incarcerated, following concerns over his behaviour. He had been held in Strangeways in Manchester.

Cregan was given four life sentences for murdering PCs Fiona Bone and Nicola Hughes as well as father and son David and Mark Short in June. He was given the rare whole life tariff for the murders, meaning he will never be able to apply for parole.

He was in the hospital wing of his Manchester prison after refusing food for weeks and was due to be transferred to HMP Full Sutton near York but because of his deteriorating mental condition he has been moved to Ashworth.

Cregan has spent most of his time in isolation.

"His head has gone" a police source said. "He can't take it any more, he's not cocky any more, what a difference in attitude. He had not been eating and was in healthcare in prison. He was just lying on his bed 24/7, doesn't talk to staff. He's not eaten for four weeks."

Before being told he would never be released from prison, Cregan had spent only short periods in jail.

Ashworth, near Maghull in Merseyside, is home to prisoners deemed criminally insane. Brady recently lost his appeal to be transferred from the hospital to a prison because he was still deemed to have a mental disorder.

Cregan pleaded guilty to the murders of Bone and Hughes in a gun and grenade attack in Hattersley, Greater Manchester in September 2012, as well as the murders David and Mark Short.