A former Metropolitan police officer allegedly used sex workers while on duty in the midst of a major investigation into behavioural standards, the Guardian can reveal.

Britain’s largest police force has been described as “institutionally misogynistic” after widespread claims that a “toxic” sexist culture has been allowed to thrive for decades.

Imran Patel resigned from his job as a police constable last year after several reports about his conduct at work over a nine-month period. He was also subject to a fraud investigation, but has been told he will not face criminal prosecution.

He is accused of using sex workers and accessing adult websites while on shift in May 2022, as former civil servant Louise Casey carried out an independent review into behaviour and culture in the force.

The Casey inquiry was commissioned by the mayor of London, Sadiq Khan, after Wayne Couzens was sentenced to a whole life term for the kidnap, rape and murder of Sarah Everard, a marketing executive.

Couzens, now 52, worked in the Met’s parliamentary and diplomatic protection command. He abducted Everard, 33, in south London in March 2021 as she walked home from a friend’s house, showing her his warrant card before pretending to arrest her for breaching Covid regulations.

Everard’s murder ignited a national conversation about misogyny within Britain’s police forces.

In March 2023, Casey, a crossbench peer, concluded that the Met was “institutionally misogynistic”.

She said: “Sarah Everard’s murder and other horrific crimes perpetrated by serving Met officers against women in London have shone a light on the shocking treatment of, and attitudes towards, women in the Met.

“Despite improvements in gender representation and increasingly flexible working practices, women are not treated equally in the workforce, with new women recruits resigning at four times the rate of all probationers; and a third of Met women we surveyed reporting personally experiencing sexism at work, with 12% reporting directly experiencing sexual harassment or assault.”

An earlier investigation by the police watchdog, the Independent Office for Police Conduct (IOPC), found that officers at London’s Charing Cross police station had sent “numerous” messages in which they joked about raping colleagues and visiting sex workers.

Last month, an undercover investigation by BBC Panorama alleged that sexist attitudes at the station persisted. One sergeant was filmed giving colleagues graphic accounts of his sex life, despite the objections of some female colleagues. The footage showed him describing a woman he met online as “so fat she had two pussies”.

Patel is also accused of committing fraud and abusing his position as an officer by taking a driving licence and money from a member of the public in August 2021.

In March 2022, a stab vest was allegedly found in his residence “without any lawful reason or reasonable excuse”.

The investigation into Patel is being led by the IOPC, after a referral from the Met’s anti-corruption unit.

An IOPC spokesperson said: “We did criminally investigate the officer over an allegation of theft but, in January 2024, decided not to refer the case to the Crown Prosecution Service.”

The Met said Patel left the force in July last year. Despite his resignation, he will face a full misconduct hearing in January.