Northumbria police is advising the public not to approach Nevins

Lee Nevins, 24, gave prison guards the slip while being treated at Sunderland Royal Hospital on Tuesday.

He is serving a minimum 17-year term at a top-security Frankland Prison, in Durham for killing Lee Jobling, 20.

Northumbria Police said they would be seeking details of the security arrangements surrounding Nevins from the Prison Service.

Angela Knotts, the victim's aunt, said she could not comprehend how Nevins had escaped and appealed to the public to trace him.

Mrs Knotts, who fostered her nephew after his mother's death, said: "I just cannot comprehend how he got away.

"There are so many slip-ups in the system to let someone as dangerous as this escape."

Nevins was jailed in 2006 for the murder of Mr Jobling on Gateshead's Leam Lane Estate after a trial at Newcastle Crown Court.

Lee Jobling died from severe head injuries

Mr Jobling's girlfriend, Samantha Clark, now 18, had been intending to tell him that she was pregnant on the night he died. The son he never knew about is now 15 months old.

Supt Gordon Milward said Nevins was taken to hospital with a hand injury and escaped after asking to go to the toilet.

He added: "I am still looking at, as part of the inquiry, the exact security measures that were in place by the Prison Service.

"My understanding is that he had a pair of handcuffs on, keeping his wrists secured and he was also secured to a guard."

Police with dogs and helicopters were used to track Nevins who Mr Milward said was dangerous, but not a threat to members of the public.

He said he was "keeping an open mind" about whether Nevins had acted alone to escape.

Fatally injured

Nevins is described as white, 5ft 11in tall, with fair hair, blue eyes and an oval-shaped face.

He has previous convictions for violence and was wearing a blue polo shirt, navy Reebok tracksuit bottoms, dark coloured overcoat, white socks and dark grey trainers when he escaped.

During his trial, the court heard Nevins and another man, who were drunk, gatecrashed a party and taunted Mr Jobling, who had been left with a limp and a brain injury after falling from a bridge in 2001.

They attacked him, ignoring his pleas for mercy, and left him blood-soaked and fatally injured.

The court heard that as Mr Jobling struggled for breath and started grunting, they began singing Old MacDonald Had A Farm.

Mr Jobling died 19 days later from head injuries on 28 April 2006.