British police have been plagued by allegations of racism in the ranks for decades - from allegations in the 1950s that they harassed ethnic minorities to accusations in the 1970s that swingeing stop-and-search powers were used disproportionately against black and Asian British people.
Years of denials of discrimination by police leaders were challenged by the Macpherson report, which found the service was institutionally racist. That inquiry focused specifically on police failings during the investigation of the racist murder of the black teenager Stephen Lawrence. It found that unwitting prejudice in part explained police bungling that allowed the killers to escape justice for the 1993 murder.
The Black Police Association came to prominence after the Macpherson report as a body to support ethnic minority officers, who are under-represented in the police service, and who say they are less likely to be promoted and more likely to be unfairly targeted for internal investigation.