The head of Britain's biggest police force on Wednesday apologised after another of his officers was convicted of sex crimes, and admitted that on average two to three officers faced criminal charges in court every week.

The Metropolitan Police is battling to restore its reputation after a serving officer was jailed for life for the kidnap, rape and murder of a young woman in south London in 2021.

Earlier this month another officer admitted 24 rapes and a string of other sex offences, prompting fresh questions about lax vetting procedures at the London force.

In the latest case, police constable Hussain Chehab on Tuesday admitted having sex with a 14-year-old girl and possessing indecent images of children.

A court was told that Chehab had even served as a school liaison officer during his time on the force.

Met Police commissioner Mark Rowley described the case as "ghastly" and conceded that the force was dealing with "more than a few bad apples".

The Met has said 1,071 of its own officers had been or are under investigation for domestic abuse and violence against women and girls.

"Most weeks there's two to three officers going to court," he said, adding that the cases were a mixture of dishonesty, violence and violence against women and girls.

He apologised for the Chehab case, but warned that more cases were likely to emerge as he implements reforms to root out the criminal and corrupt in the Met's ranks.

"We are going to be surfacing more," he told the London Assembly's police and crime committee.

Last week campaigners dumped 1,071 rotten apples, representing the number of officers being probed, in front of the Met's New Scotland Yard headquarters.

"We've been told time and time again that it's just one bad apple here and there, but this is actually a fundamental problem right across policing," said Ruth Davison, head of the domestic abuse charity Refuge, which organised the protest.

She called for any officer facing formal allegations to be suspended while an investigation takes place.

Wayne Couzens, who served in the Met's armed unit protecting MPs and foreign diplomats, was jailed for life for the kidnap, rape and murder of Sarah Everard.

Serial rapist David Carrick, who will be sentenced next month, served in the same unit.