The Sun newspaper said the 52-year-old suffered severe brain trauma in the attack at HMP Frankland, Durham, on February 26.

The former school caretaker, who murdered 10-year-olds Holly Wells and Jessica Chapman in 2002, had been kept on life support in hospital after being hit repeatedly over the head by an inmate armed with a metal bar.

Huntley’s life support was switched off at lunchtime on Friday after brain tests showed he was in a vegetative state, The Sun reported.

The attack left Huntley blind, the newspaper said, and it quoted a source saying: “Huntley never recovered from the battering and never stood much of a chance of doing so.”

Murderer and rapist Anthony Russell, 43, reportedly shouted “I’ve done it, I’ve done it” after Huntley was attacked in the recycling area of the prison.

Ian Huntley murdered Holly Wells, left, and Jessica Chapman

Ian Huntley. Photo: Toby Melville/PA

News in 90 seconds – Saturday, March 7

Durham Constabulary has not identified the suspect but it said on the day of the attack that a man in his mid-40s had been detained.

After the attack, Huntley’s only daughter Samantha Bryan, 27, told The Sun on Sunday of her father: “There’s a special place in hell waiting for him.”

Huntley murdered Holly and Jessica after they left a family barbecue to buy sweets in Soham, Cambridgeshire, on August 4 2002. He dumped their bodies in a ditch.

Russell was sentenced to a whole-life tariff in 2021 for the murders of Julie Williams, 58, and her son David Williams, 32, at separate flats in Coventry, and pregnant 31-year-old Nicole McGregor, who was found in woodland near Leamington Spa three days later.

Russell also raped Ms McGregor.

Huntley’s life sentence recommended he serve at least 40 years for the Soham murders.