A CHILD sex killer murdered at a maximum-security prison near York was taken hostage before being attacked by a fellow inmate.

Drug-addict robber Damien Fowkes, 35, was today arrested over the murder of Colin Hatch, 38, at HMP Full Sutton.

Hatch, who was serving life for the 1994 killing of seven-year-old Sean Williams, was killed at the prison on Tuesday night.

East Yorkshire MP Greg Knight tonight demanded a full inquiry by the Home Office and said prisoners jailed for offences against children may have to be segregated from other inmates.

Humberside Police have launched a murder investigation and said a 35-year-old man had been arrested.

He was named by the Press Association as Damien Fowkes, who was jailed for life at Northampton Crown Court in 2002, with a minimum of 12 years, after three robberies in four days.

The arrested man was last night still being held at the prison on suspicion of murder. Police said he would be transferred to a police station “at a later date”.

Hatch was jailed for life after killing Sean Williams while on parole, aged 21.

He abducted, sexually assaulted and choked Sean to death after luring him to his tower block home in Norfolk Close, Finchley.

A postman found the body taped in bin bags inside a lift. The crime happened just 11 weeks after Hatch was released from a three-year jail sentence for attacking an eight-year-old boy.

He had a string of previous convictions from the age of 15 for attacks on six young boys.

Mr Knight said he would ask the Home Secretary, Theresa May, to hold an inquiry into how the incident came to happen in a maximum security prison.

He said he was satisfied the prison was “very good” at preventing escapes, but said the Prison Service may have lessons to learn.

He said: “It does raise the question whether criminals convicted of child offences need to be segregated from other prisoners. As repulsive as these acts are it’s a duty of the state to see that prisoners are protected from other prisoners.”

At the last unannounced inspection of HMP Full Sutton, in 2007, inspectors called it was a “commendably stable and largely safe environment”.

They said the security department was well staffed and impressively organised, and the work of the intelligence unit was particularly noteworthy.

Juliet Lyon, director of the Prison Reform Trust, said: “Prisons have a duty to hold all prisoners safely and securely, regardless of the crimes they have committed. Fortunately, a death such as this is a rare event.”

A police spokesman said the prison phoned them at 7.24pm on Tuesday reporting “an incident happening” then phoned again at 8.07pm to say the man had died.

Hatch’s family has been informed and a post-mortem examination was due to be carried out today.