Police are trying to track down a man who went missing three weeks ago from the John Howard Centre, a secure mental health unit in Kenworthy Road, Homerton.

They have warned members of the public not to approach James Frank Lisbon, 34 - who is the subject of a hospital order. Mr Lisbon went missing from the John Howard Centre, a secure mental health unit in Kenworthy Road, Homertonon Sunday August 4 after failing to return from unescorted leave.

He is described as white, 6ft tall and of large build and was last seen wearing a navy blue short sleeved top, navy tracksuit bottoms and a white baseball cap.

He has scars on both arms and a tattoo on his right arm.

Police are concerned for Mr Lisbon’s wellbeing as he requires treatment.

Anyone with any information should call 999.

The unit at the John Howard Centre is for people with learning disabilities and mental health difficulties, and is run by the East London NHS Foundation Trust in Hackney.