The escape of convicted armed robber Ashley Waterman from St Bernard's Hospital in Ealing has forced mental health chiefs to step up security at the secure unit.
Officials at West London Mental Health Trust, which also manages the Lakeside facility at West Middlesex Hospital, have promised to carry out a full investigation after Waterman - who is still at large - escaped from a secure unit in Uxbridge Road.
In a statement, a trust spokeswoman said: "Following the escape the Trust is liaising closely with the Department of Health and the Ministry of Justice and, based upon an interim risk assessment and subsequent immediate actions, security arrangements have been increased.
"A full investigation will be completed into the circumstances of the escape, to ensure that any learning which will improve security within the unit are actioned. The trust is unable to comment upon individual patients for reasons of confidentiality."
Asley Waterman, 20, who is serving five years for armed robbery, had been incarcerated at Feltham Young Offenders' Institution but was transferred due to mental health issues.
Described by police as 'dangerous', he has been on the run since staff at the hospital discovered he was missing in the early hours of Saturday morning.
He is a white male, 5ft 8ins tall, slim build, short light brown hair, fair complexion and when last seen was wearing a grey hooded top. He is known to have connections in Paddington.
Waterman's escape comes just over two years after terror suspect Zeeshan Siddiqui, of The Vale, Heston, jumped from a window at Lakeside, where he was being held.
Security chiefs are still hunting the former Cranford Community College student, who is said to have been school friends with Britain's first suicide bomber, Asif Hanif.
Police ask anyone who may know of Waterman's whereabouts, or who may have seen him, to call Ealing Police on 0208 246 2058.
If you wish to remain anonymous please call Crimestoppers on 0800 555 111. For an immediate sighting, call 999.
Do not approach him.