A review of cases where people with mental illness have died or been seriously hurt in police custody, such as that of musician Sean Rigg, has been launched.
Half of the deaths in police custody in 2011/12 were people who had mental health problems, and Scotland Yard has commissioned a review to look at cases over the past five years involving serious injury or death.
Earlier this year the jury at the inquest into Mr Rigg's death found police officers used "unsuitable'' force after arresting the 40-year-old schizophrenic for attacking passers-by and police officers in Balham, south London, on August 21, 2008.
Physically fit Mr Rigg was being held at Brixton police station when he died of cardiac arrest.
After the inquest, a report by police watchdog the Independent Police Complaints Commission (IPCC) said: "Sean Rigg's death is a symptom of a deeper problem: the linkage between mental illness and deaths in or following police custody."
Its own original investigation into the death, which found that officers had acted properly, was criticised by Mr Rigg's family as "extremely poor and ineffective" and is being reviewed by the IPCC.
This information will feed into the commission's inquiry, which is being led by Lord Victor Adebowale, chief executive of the care services provider Turning Point. It is expected to be completed in February, when the final report will be presented to the Met and made public.
Commissioner Bernard Hogan-Howe said: "A number of cases have highlighted concerns with how police respond to people with mental health conditions. I want to know that we are doing everything we can to get this right. That is why I've commissioned this independent review.
"This is not a matter for the police alone and the roles of partner agencies will be explored by the commission."
He said he was writing to a number of families about the review, but Scotland Yard would not reveal who had been contacted.