A reward of up to £3,000 is being offered by the charity Crimestoppers for information on the whereabouts of Joseph Bagley, who is on the run and considered dangerous.
Bagley, who is 66 years old, has breached the terms of his licence.
He was jailed in 1978 for the murder of a taxi driver.
In January this year he was released from prison on a supervised life licence. He was living at approved premises in Maidstone, Kent, but failed to return for his curfew during the evening of Sunday 12 May. He has not been seen since.
Joseph Bagley is believed to have links to the Kent, Surrey and Buckinghamshire areas – and also Scotland.
He is described as white, with blue eyes and grey hair. He is approximately 5 foot 11 inches tall and of medium build. He has a memorial tattoo on his left arm and a scar on one of the fingers on his right hand.
It is likely that Bagley has changed his appearance which is why a forensic artist has produced images of what he might look like with different hair or no moustache.
Glenys Balchin, Surrey Regional Manager at the charity Crimestoppers, said: “We believe everyone has the right to feel safe from crime, whether at home, in the workplace or when out and about.
“Bagley has a history of violence so it’s crucial that if you know where he is or spot him, please let us know immediately and do not approach him. He has links to Kent, Surrey, Buckinghamshire and Scotland and may well be in hiding in other parts of the UK that he’s familiar with.
“Please help us to keep our communities safe and do the right thing by contacting Crimestoppers if you know of Bagley’s whereabouts. In over 30 years our charity has always kept its 100% anonymity promise to everyone who trusts us with their crime information.
“No one will know you contacted us and it could be your information, however small, that makes a difference. Our UK Contact Centre is open 24/7 on 0800 555 111 or you can use our anonymous online form at www.crimestoppers-uk.org.”