A violent bank robber known as the "Skull Cracker" has been spotted in Twickenham, south-west London, police have said.
Michael Wheatley, who went missing while on temporary leave from an open prison in Kent, is due to serve 13 life sentences and gained his nickname for pistol-whipping his victims during armed raids.
Scotland Yard said officers were called to an address in Twickenham at 7.55pm last night "following a sighting of Michael Wheatley".
A statement from police said: "Upon arrival, officers searched the area. Wheatley was not found.
"Inquiries are continuing. The Met continues to work closely with Kent Police to trace Wheatley who is being sought for arrest by police."
Anyone who sees Wheatley should call 999 but not approach him, police said.
The sighting came as the Prisons minister, Jeremy Wright, said there would be a review of this latest high-profile case of a someone absconding from an open prison. "We are not prepared to see public safety compromised," he said. "The system has been too lax up to now and we are changing that."
Wheatley failed to return on Sunday to the Standford Hill prison on the Isle of Sheppey to continue serving his life term imposed in 2002 for raids on banks and building societies while on parole. He has links across the south-east of England.
"It is ludicrous that a prisoner serving a life sentence is even in an open prison where they can simply walk out," said the Tory MP Philip Davies. "As far as I am concerned whoever allowed him to be in an open prison should be sacked; it is a complete disgrace."
The Ministry of Justice said that prisoners on day release will be given GPS tags from the autumn after a series of embarrassing incidents. It follows the case of Sean Bradish who was jailed for three life terms in February after robbing banks while on day release – then faced no action when he turned up hours later. In a parole board report, he was praised for taking the opportunity to "rebuild relations with close friends and family". It stated there was no evidence of concerning behaviour or association with criminal associates.
The ministry had already promised a review into day release after a convicted killer stabbed a pensioner to death who intervened in the robbery of an elderly neighbour. Ian McLoughlin was jailed for life last year.