Andy George, president of the National Black Police Association, said racism had not gone away in the past 20 years but had simply been pushed underground.
Speaking to The Independent, he asked: “How many times can we say it’s a few bad apples, we’ve dealt with them, things are great? There’s a wholesale systemic issue with culture.”
Fresh concerns have been sparked by evidence heard in the trial of three current and former Metropolitan Police officers, over jokes about rape, domestic violence, Muslims and racial minorities in a WhatsApp group containing Wayne Couzens.
It follows a watchdog report that exposed racism and misogyny at Charing Cross police station and the sacking of another officer who was found to have used a racial slur in messages to a colleague who photographed the bodies of two murdered Black women.
The latest case resulted from Couzens’ phone being seized following the murder of Sarah Everard.
Messages were discovered showing officers calling ethnically diverse areas of London “s***holes” and “filthy”, with one saying he “felt like a spot on a domino”. Other messages appeared to joke about the prospect of leaving Muslims to die in a terrorist bombing.
The officers, who pleaded not guilty to all charges, denied racism and said the messages were only “humorous banter”, with one defendant calling the prosecution “ridiculous”. The case has been adjourned until September.
Mr George told The Independent: “That attitude just shows that in the last 20-plus years all we’ve done with racism is pushed it underground.
“We’ve taken it out of canteens, out of mainstream documents and put it on WhatsApp groups and anonymous police social media accounts.
“We’ve made it something that you can’t say in the open anymore, but that people still obviously think and feel is acceptable – that’s the worrying bit.”
Mr George said that the evolution of policing over the past two decades, which has seen police ascribe to new ethics codes and undergo equality and diversity training, had “ suppressed racism to a certain degree”.
But he warned: “How widespread those WhatsApp groups seem to be and what is said on them shows that we have a culture that normalises racism, misogyny and other discriminatory behaviours.”
The current case was sparked when investigators seized Couzens’ phone following the murder of Ms Everard, and the court heard that no other officers had raised concerns about the WhatsApp group.
Mr George called for forces to be more proactive in taking action, warning that some “see discrimination, racism and misogyny as a PR issue they have to contain”.
“Silence is permission and there’s a silent majority that allows things to happen,” he warned. “They know it’s wrong but are afraid to come forward and say anything. That’s the culture that needs to be done away with – if we challenge these behaviours at their lowest level, at the first opportunity, then people will understand they can’t get away with it.”
The charity, Justice, said there had been an “unacceptable” amount of progress since the murder of Black teenager Stephen Lawrence in 1993, which triggered a report accusing Scotland Yard of institutional racism.
Legal director Stephanie Needleman said: “These messages speak to a horrific culture in the Metropolitan Police. The new Metropolitan Commissioner must urgently get a grip on this issue, and ensure that racism and discrimination among the force is urgently rooted out. London’s communities impacted by discriminatory policing practices deserve better”.
The Stand Up to Racism organisation said the number of cases involving racism showed that such messages were “not isolated incidents” and called for “root and branch change”.