Weightlifter Brian Trinder, 49, who was jailed for life in 1973 for the murder of five-year-old Samantha Clifford, escaped from Leyhill Open Prison, near Bristol, on Monday.

He had been on an industrial cleaning work placement within the prison grounds. He was last seen at about 3pm and missing from roll-call at 5pm.

Avon and Somerset police said that although Trinder is not classified as dangerous, they would advise the public "not to approach him, but to contact the police immediately if he is sighted".

Trinder, from Southall, Middlesex, is described as 5'7", of stocky build, with blue eyes and dark brown cropped hair. He is clean-shaven and heavily tattooed on his arms and body, including stars on his earlobes.

'Not classified as dangerous'

The former lorry driver strangled Samantha, from Bexhill in East Sussex, in 1972, after he discovered her sister Terry - Trinder's ex-girlfriend - was seeing another man.

During the murder trial at Maidstone Crown Court, Trinder admitted raping an air hostess in London and assaulting a married woman.

Since then, he has been categorised by the Home Office as a Category D prisoner who is not dangerous.

However, he has staged a prison escape before. In 1988 he hid in a rubbish skip being taken out of Horfield Prison, Bristol.

He was finally found in Cardiff when his car plunged 40 feet down an embankment at Llanedeyrn in the city.

Being prepared for release

Following a Parole Board recommendation in 1993, Trinder was transferred to Leyhill Open Prison near Bristol - a low-security prison known for its low rate of absconding.

The Prison Service said the transfer to an open prison, despite the escape, would have been justified by Trinder's behaviour since being recaptured.

"It is essential for life sentence prisoners to spend a period prior to release in open conditions as an important part of the rehabilitation process," said a spokesman.

"It builds up links with the community and enables them to progress back into the community before release.