A violent armed robber dubbed “the skull cracker”, who was jailed for life for a string of offences including one in Royston, is on the run from police after absconding from an open prison.

Michael Wheatley, 55, failed to return to HMP Standford Hill, an open prison on the Isle of Sheppey, Kent, on Saturday.

He was given 13 life sentences in 2002 for a string of brutal raids on banks, including one in Royston. He was given his nickname after pistol-whipping victims during the raids.

Wheatley was spotted in Twickenham, West London, on Monday night, but evaded capture and remains at large.

Police say anyone who encounters Wheatley should not approach him and dial 999 immediately.