Croydon police have renewed their appeal for information about a patient missing from Southleigh Community Hospital since Tuesday.
Police have warned that Mark Ricketts, 52, has a history of violence and should not be approached if seen.
Mr Ricketts is described as a black male of stocky build, 6ft 2 inches tall with greying, black hair and was last seen wearing grey bottoms and a dark baseball cap.
He requires regular medication and his behaviour may be affected without it.
Detective Constable Louis Murphy said that members of the public should call 999 immediately if they see Mr Ricketts.
DC Murphy said that police were unsure of where Mr Ricketts may have gone after absconding from hospital.
Contact Croydon Police on 101 with information and quote 18MIS037624.