Police are urgently appealing for assistance in locating a convicted murderer, who is wanted for emergency recall to prison - and they now believe he may be in London.

William Kerr, 53, who speaks with a Scottish accent, needs to be arrested and returned to prison as a matter of urgency.

If they see him, people are asked not to approach him but instead to call the police immediately on 999.

Kerr was jailed for life for murder at Leeds Crown Court on June 26, 1998, and released on licence on January 23 of this year.

The National Offender Management Service contacted North Yorkshire Police for assistance after Kerr absconded from approved premises in Hull.

Following extensive enquiries, officers believe that Kerr has travelled to the London area where the Metropolitan Police are assisting the search.

Two photographs of Kerr have been circulated to the press and published on social media.

Detective Inspector Eamonn Clarke, of North Yorkshire Police, said: "To assist our already extensive efforts to trace William Kerr, I am urging people to keep an eye out for the man in the photographs. We believe he is now in the London area and he may be trying to book into a hostel or other accommodation using a false name as he has done previously.

"We ask that you do not approach Kerr, as he is considered dangerous. You should contact the police straight away on 999 and officers will be dispatched to arrest him or investigate the sighting."

DI Clarke is also appealing directly to Kerr: "William, you know you have breached your licence conditions, and by continuing to do so you are only making things worse. It is now time to do the right thing and hand yourself in to the police."

If you have seen William Kerr or have information about his current whereabouts, please dial 999 and pass details to North Yorkshire Police stating the "William Kerr appeal".

If you would prefer to remain anonymous, please contact Crimestoppers on 0800 555 111, quoting North Yorkshire Police reference number 12150049525 and say it is "urgent".