Child killer Mark Bridger has been attacked by a fellow prisoner less than two months into his whole life sentence.
The 47-year-old, who was jailed in May for abducting and murdering schoolgirl April Jones, was slashed with a makeshift blade during the attack as he walked along a gangway at HMP Wakefield in West Yorkshire.
Bridger reportedly suffered facial injuries and was taken to a local hospital where he was given stitches.
Prison officers stepped in to save him from further injury, according to The Sun newspaper.
A spokesman for Her Majesty's Prison Service confirmed a prisoner had been injured and taken to hospital during the attack, which is now being investigated by the police.
Bridger kidnapped April before sexually abusing and murdering her and disposing of her body last October.
Police believe he dismembered the five-year-old's body before dumping the body parts at various locations in the hills, rivers and forests surrounding his home.
He was given a whole life sentence by judge Mr Justice Griffith Williams after a jury found him guilty following a month-long trial.
April had been playing with friends close to her home on the Bryn-y-Gog estate in Machynlleth, Powys, when Bridger enticed her into his car.
Following his arrest, detectives found numerous indecent images on his computer and traces of April's blood around his home.
HMP Wakefield is a high-security prison which houses an average of 740 male inmates, many of whom are serious sex offenders.
The jail houses a number of child killers including Roy Whiting, Levi Bellfield and Mick Philpott.
Bridger had previously been kept away from other prisoners for his own safety, as attacks on notorious inmates are not uncommon in Britain's jails.
Despite tight security surrounding high-profile inmates - including segregation for paedophiles and child killers - attacks with makeshift blades and other improvised weapons do take place.
Ian Huntley, the killer of Holly Wells and Jessica Chapman, was attacked at Wakefield when a fellow prisoner, murderer Mark Hobson, threw a bucket of boiling water over him in September 2005.
Huntley was moved to HMP Frankland in January 2008, where his throat was slashed by another inmate in March 2010.
Roy Whiting, killer of schoolgirl Sarah Payne, was stabbed by a fellow inmate in Wakefield in July 2011.
Double murderer Gary Vinter was given an indefinite sentence with a notional minimum five-year term after he admitted attacking Whiting with a sharpened toilet brush handle.