Hundreds of British police officers have been disciplined or dismissed in recent years for sickening uses of social media, including an alleged “sexualised” conversation with a 13-year-old and sharing photographs of dead people, openDemocracy can reveal.

Other cops were found to have made homophobic and racist comments online, while a PC in Leicestershire was let off with a warning after allegedly sending a picture of a person performing a sex act with an animal.

Data released to openDemocracy under the Freedom of Information Act shows that the vast majority of officers involved in such cases since 2018 were allowed to keep their jobs, with just 33 of the 257 getting the sack.

Some 36 police forces across the UK responded to the request for information – although 12 others failed to do so – stoking fears that the problems with policing extend beyond London’s troubled Metropolitan Police.

For those that failed to provide a response, openDemocracy searched through logs of misconduct meetings and hearings on police forces’ sites, although the availability and the quality of data varied.

In one case, the data revealed, a police sergeant in West Yorkshire allegedly shared a “racist video” on a work WhatsApp group, but remained in post.

In a chilling precursor to the 2020 cases of Nicole Smallman and Bibaa Henry in west London, in which officers were jailed after sharing pictures of the sisters’ dead bodies in a park, a West Yorkshire officer in 2015 was given a “final written warning” after allegedly taking a photo of a dead person and sending it to colleagues.

In a similar case last month, an Avon and Somerset police officer was dismissed for sending a photo of a dead woman to a colleague on WhatsApp.

And an officer at Cheshire Constabulary took an image of a detainee from a police system and shared it with colleagues via WhatsApp.

A Kent Police officer shared a meme that was “likely to be construed as racially offensive or discriminatory” on WhatsApp, and was given a final written warning.

In Thames Valley Police, an officer was dismissed after “extreme sexual and violent images” were found on his phone, while another posted “pornographic, racist and homophobic” images on WhatsApp – but kept their job.

A third officer at the force received disciplinary action for “harassing his ex-partner”.

Other forces revealed a litany of disturbing incidents, including some that resulted in police officers being sacked.

They include an alleged “sexualised” conversation an officer had with a 13-year-old online, and a PC in Norfolk who uploaded “indecent images” to an unspecified social media platform.

The findings follow the resignation of Cressida Dick – the country’s most senior police officer – as Metropolitan Police commissioner, amid a storm of controversies that have engulfed the force.

They include the revelation that police in the Met shared WhatsApp messages where they joked about hitting and raping women.

Other messages showed that officers based at London’s Charing Cross police station had mocked disabled people, ethnic minorities and the Black Lives Matter movement.

Announcing her resignation last night, Dick also acknowledged that the murder of Sarah Everard by a serving police officer last year had “damaged confidence” in the force.

Before Everard’s murder, the man had shared abusive messages with five of his colleagues in the Met and was known as “the rapist” by former colleagues at a different police force.

openDemocracy’s investigation now reveals that abusive messages are a widespread issue among police forces across the UK.

Despite the revelations about abuse by serving Metropolitan Police officers, only 25 allegations over social media misconduct at that force have resulted in any kind of disciplinary action since 2018.

Like many forces, the Met refused to disclose details of the cases, claiming that this would breach rules around “personal data”.

Last night, Dick’s resignation from the Met was met with calls for “serious reform” by opposition politicians.

The mayor of London, Sadiq Khan – who triggered Dick’s resignation by making clear he had lost confidence in her leadership – said the revelations about officers sending abusive messages had “shattered public trust and confidence” in the force.

“We must urgently rebuild Londoners’ trust in the Met and root out the racism, sexism, homophobia, bullying, discrimination and misogyny that still exist,” he said. “To do that, change must start from the very top.”

Labour’s shadow home secretary, Yvette Cooper, said: “This isn’t just an issue for London – the home secretary must support reforms to raise standards across the country to support the essential work the police do.”