The police watchdog has begun an investigation into the death of man after he was held under restraint by police.

The 35-year-old man, who appeared to be having a mental health crisis, became unwell while being detained by officers in London.

Scotland Yard said they had been called to reports of a person trying to get into gardens behind homes in Polsted Road, Lewisham, at around 2.20pm on Friday.

Footage from body-worn cameras showed the man was in an agitated state, according to the Independent Office for Police Conduct (IOPC).

He was restrained at the scene and paramedics called, but had become unwell by the time medics arrived.

He was taken to Lewisham Hospital by ambulance where he died..

The man has not been named, but his next of kin have been informed. A post-mortem will be carried out in due course.

Investigators at the IOPC watchdog have begun reviewing body-worn video footage from all officers who attended the incident and are carrying out door-to-door enquiries in the area.

Regional director Jonathan Green said: "My thoughts are with the man's family and friends and to all those affected at this time and we will look to issue more information when appropriate."

Detective Chief Superintendent Tara McGovern of Lewisham Police said: "Our thoughts are with the family of the deceased at this extremely difficult time.

"Where a person dies following contact with the police it is right and proper that police refer the incident to an independent body to review the circumstances surrounding the death, which happened immediately in relation to this incident.

"We are reassured to know that the deceased's family is being supported and we are offering support to the officers involved in the police response."We are, and will continue to, provide our full support and co-operation to the IOPC investigation."