Met Police Chief Sir Mark Rowley has said it is "crazy" that he is unable to sack "toxic" officers who have broken the law but also admitted vetting procedures have been inadequate.
The force's Commissioner has said that "there are some very worrying cases" of officers who've committed crimes and yet he is unable to fire them, adding: "It's crazy."
Appearing on the BBC's Today programme, he was questioned about a report that revealed 150 officers were under investigation over allegations of sexual misconduct or racism.
"We have some very worrying cases with officers who've committed criminality whilst police officers and yet I'm not allowed to sack them. It's sort of, it's crazy."
And referring to the 150 police officers currently under investigation he added: "The investigation needs to take place - not all of those cases will have have a case to answer, but many of them will.
"We've got some officers who we sacked, but other legal bodies, who have a power to reinstate them, did.
"So I've got officers who we determined shouldn't be police officers and yet I have to keep them. It sounds bizarre - I'm the commissioner, yet I can't decide who my own workforce is."
Commissioner Rowley, who took over from Dame Cressida Dick in September last year, said that "vetting wasn't good enough".
"There were cases where there were warning signs and our vetting wasn't good enough. That's why we're beefing that up," he said.
Earlier this week, Rowley said the force has "a practical plan for turning things around" during a speech at the Institute of Engineering and Technology in Westminster on Tuesday evening.
It comes after a watchdog reportedly found that the force's anti-corruption systems are not fit for purpose and a damning review of disciplinary procedures by Baroness Casey revealed officers and staff were getting away with misconduct and breaking the law, in a conduct system that is itself racist and misogynist.
In his speech, Rowley outlined some details of the working reform plan, including building a data-led list of tens of thousands of violent predators and strengthening neighbourhood policing. He said: "Today is about solutions and plans. We must change for our communities, and for our officers and staff who serve them."
"We are taking our first steps on a journey of reform in the Met," he later said. He added: "I expect to be held accountable for how that transformation of London's police service evolves in the weeks, months and years ahead.
"We have a practical plan for turning things around. We have tens of thousands of hard-working men and women who I know will ensure the Met delivers more trust, less crime and high standards."
