The Met has apologised to the family of a mentally ill black man who died in custody, after one of the officers involved was cleared of misconduct.
Kevin Clarke, 35, was suffering from an acute behavioural disturbance when he was restrained by up to nine officers in Lewisham in 2018.
The force broke regulations by holding misconduct proceedings without telling his family or the police watchdog.
Cdr Bas Javid apologised and said it had been an administrative error.
In an interview for the BBC's Panorama programme, Cdr Javid admitted that the force still had an issue with "racial discrimination, bias and prejudice".
Mr Clarke had been diagnosed with paranoid schizophrenia as a teenager and was living in supported accommodation when he died.
In March 2018 he suffered a relapse and police were called.
Mr Clarke had been lying on the ground and attempted to get to his knees before being restrained by up to nine officers. He was handcuffed and legs restraints were applied.
Police body-worn video footage reveals Mr Clarke repeatedly told officers "I can't breathe", before being made to walk to an ambulance, still bound at the knees while barely conscious.
Restraint expert Eric Baskind told Panorama: "There is absolutely no justification at all for restraining him... he's not being aggressive… he's suffering from a mental health crisis, and what they've done is just totally wrong and dangerous."
An inquest recorded a damning narrative verdict in October last year, concluding the way Mr Clarke was restrained was inappropriate and had contributed to his death.
Mr Clarke's sister Tellecia Strachan said: "A lot of [the officers] have said that they wouldn't change their actions if they were to do it again… and to me, that's like no lessons have been learned."
The Independent Office for Police Conduct (IOPC) had instructed the Met to hold a misconduct meeting over the way the senior officer at the scene handled Mr Clarke's restraint.
But the Met failed to tell either the IOPC or Mr Clarke's family the date of the hearing, at which the officer was cleared.
Cyrilia Davies Knight, solicitor to the Clarke family, said it had been "truly shocking" the process had been allowed to go ahead without the family.
"I think [they] might have been able to understand or stomach it a bit more had the outcome been different but here we have an officer having her conduct reviewed without the disciplinary body who brought her there in the first place and without the family who have an interest - and the outcome is there was no case to answer," she said.
The IOPC now wants the Met to hold the process again.
A spokesperson for the police watchdog said: "The IOPC has taken the unusual step of challenging the misconduct meeting as the Metropolitan Police Service failed to notify us or Mr Clarke's family of the date of the hearing, so neither we nor the family were able to attend as the regulations provide for.
"The regulations exist to ensure the system is transparent and fair, and failure to follow them deprived the deceased's family of their right to be able to ask questions at the hearing and for the IOPC to make representations."
Mr Javid said the family had been called by a senior officer and an apology was offered. He added that there had been an "administrative error", and said there was "nothing in what I've seen" to suggest "there was any attempt" to exclude the IOPC or the family.
The inquest jury was not asked to consider whether Mr Clarke's race was a factor, and the Met said there was no evidence it was.
Black people are twice as likely as white people in the UK to die in custody, and, in London, three times more likely to have force used on them.
The Met's use of force figures also reveal its officers are consistently more likely to cite a black person's size and build as a reason for using force than they are with white people.
Prof Leslie Thomas QC, counsel for the Clarke family at the inquest, told Panorama the officers' reaction to Mr Clarke, who was over 6ft (1.82m) tall and weighed 19st (120kg), may have been affected by "fear of what they see - a big, black man".
He added: "I didn't need to spell out to the jury that race was a factor.
"To my mind, race was the elephant in the room. Sometimes you don't need to spell out the obvious."
Asked to explain why black people were more likely to have force used on them, Cdr Javid said: "I explain it by accepting that that's disproportionate. That it's not right. We need to understand the reasons why.
"Is there racial discrimination and bias and prejudice within an organisation? Absolutely."
When asked by the BBC: "In yours?" he replied: "Yes, there is, yes."
Panorama: I Can't Breathe: Black and Dead in Custody Will be broadcast at 19:35 GMT on BBC One and will then be available on the BBC iPlayer.
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