A VIOLENT armed robber dubbed “the Skull Cracker” who has gone missing after temporarily being allowed out of prison struck in Hampshire.

Michael Wheatley, 55, who was given 13 life sentences in 2002 for a string of brutal raids on banks, failed to return to HMP Standford Hill open prison on the Isle of Sheppey, Kent Police said.

Wheatley raided 13 building societies and banks over 10 months in 2001 and 2002 while on parole from a 27-year sentence for other robberies.

The robberies between June 2001 and April the following year were mainly on small branches in areas Wheatley knew.

He earned his notorious nickname after pistol-whipping victims, including a 73-year-old woman, during the raids.

The first was just three weeks after he was paroled from his first prison term.

The Old Bailey heard at the time he would often grab a female customer, putting the pistol to their head, leaving many mentally anguished.

His raids netted him more than £45,000.

He was given a five-year sentence on each of the firearm offences to run concurrently with the life sentences on each of the robbery charges. He was ordered to serve a minimum of eight years before being eligible for consideration for parole.

The court was told how he robbed a clerk at the Bishop's Waltham branch of Halifax building society at gunpoint.

Kathleen Knights told the Daily Echo how Wheatley pointed the gun inches from her face before demanding the cash and escaping with an undisclosed sum.

Mrs Knights had to be taken to Southampton General Hospital after Wheatley hit her on the back of the head with the gun as he made his escape.

A Kent Police spokesman said: ''Anyone with any information or who sees Wheatley is asked to not approach him and to instead contact police by calling 999.''

The spokesman said Wheatley, originally of Limehouse in east London, has links across south east England.

Wheatley admitted 13 charges of robbery and 13 of possessing an imitation firearm - a blank firing semi-automatic pistol - in October 2002.

Conservative backbencher Philip Davies said that whoever had allowed Wheatley out of prison was ''a berk'' and questioned why he was in an open prison in the first place.

The MP for Shipley in West Yorkshire said: ''It is completely ludicrous that a serving life sentence prisoner is even in an open prison where they can simply walk out.

''As far as I am concerned whoever allowed him to be in an open prison should be sacked, it is a complete disgrace.

''The top priority for the prison service should be the protection of the public. (Justice Secretary) Chris Grayling needs to put in charge of the prison service someone who will see protection of the public as a top priority.''

A Prison Service spokesman said: ''This is now a matter for the police and we are supporting them in their investigation.

''We are toughening up the release on temporary licence scheme so that prisoners will be subject to stricter risk assessments and tagged.''

The Ministry of Justice has promised a full review of the case.