Sarah Everard’s murderer Pc Wayne Couzens has been linked to an alleged indecent exposure incident as far back as 2015, according to the police watchdog.

The Independent Office for Police Conduct (IOPC) has launched an investigation into alleged failures by Kent Police to investigate.

A probe is also ongoing into alleged failures by the Metropolitan Police to investigate two allegations of indecent exposure linked to Couzens in London in February this year, with two officers under investigation for possible breaches of professional standards.

The watchdog said a total of 12 gross misconduct or misconduct notices have so far been served on police officers from several forces relating to the Couzens case.

Other probes are under way into how the constable twice suffered head injuries while in custody following his arrest, allegations that a probationary Met officer shared an inappropriate image and claims officers shared information linked to the prosecution.

It comes as Britain’s most senior police officer, Met Commissioner Dame Cressida Dick, said “no words can adequately express the profound sadness and anger and regret” felt by everyone in the force about 33-year-old Ms Everard’s kidnap, rape and murder.

Speaking outside the Old Bailey, where Couzens pleaded guilty to murder on Friday, Dame Cressida said her thoughts were with the victim’s family.

“I was able to speak to them earlier today and say again, how very sorry I am for their loss and for their pain and their suffering,” she said.

“All of us in the Met are sickened, angered and devastated by this man’s crimes.

“They are dreadful. Everyone in policing feels betrayed.”

The force said Couzens passed vetting procedures and a review after his arrest found no information available at the time that would have changed the decision.

He joined the Met in September 2018 from the Civil Nuclear Constabulary (CNC) before moving to the Parliamentary and Diplomatic Protection Command in February 2020, where his main role was to patrol diplomatic premises, mainly embassies.

Couzens kidnapped Ms Everard as she walked home alone from a friend’s house in Clapham, south London, on the evening of March 3 after finishing a 12-hour shift, before raping and murdering her.

The Met said he was never subject to any misconduct proceedings during his time in the force, who stopped paying him after he pleaded guilty to rape and kidnap last month.

Couzens now faces internal misconduct proceedings as well as a possible whole life sentence.

Crown Prosecution Service specialist prosecutor Carolyn Oakley said Couzens is yet to reveal what he did to Ms Everard.

“Wayne Couzens lied to the police when he was arrested and to date, he has refused to comment,” she said.

“We still do not know what drove him to commit this appalling crime against a stranger.”