Black and ethnic minority police officers are up to five times more likely to be the subject of corruption or internal misconduct investigations compared to their white colleagues.
A study commissioned by Greater Manchester Police (GMP), which examined three of Britain's biggest police forces, revealed that complaints by black and Asian officers that they are routinely subject to racially discriminatory inquiries by their employers were well-founded.
The National Black Police Association called for urgent intervention by ministers to address the problem, which it said was hampering efforts to increase ethnic minority recruitment and blocking the advance of non-white officers into senior ranks.
Its president, Charles Crichlow, said: "The findings of this report vindicate concerns raised over many years regarding officers from different backgrounds being treated differently and unfairly.
"There is now an opportunity to use this evidence as a catalyst for tackling these issues once and for all."
He said there was no evidence to suggest that allegations against black and Asian officers were more likely to be proved, while in some cases they were much less likely to be upheld.
According to the study carried out by the University of Manchester, leading forces are still struggling to come to terms with diversity more than 13 years after the MacPherson Report found evidence of institutional racism in the Metropolitan Police.
Researchers interviewed officers and investigators and analysed data concerning internal allegations of wrongdoing from West Midlands Police, the British Transport Police (BTP) and GMP from 2007-11.
The authors found that the rate of corruption allegations against black and ethnic minority non-uniformed West Midlands staff was six times that of their white colleagues and five times higher among officers.
In Manchester, Asian officers were nearly three times more likely to be investigated in corruption inquiries compared to whites.
Black BTP officers were 2.7 times more likely to be investigated than any other ethnic group.
There was particular criticism of GMP.
It was the subject of the BBC's The Secret Policeman documentary in 2003 which revealed evidence of racism among recruits, including one officer dressing up in a Ku Klux Klan hood.
The report found "compelling" evidence of disproportionality in the treatment of ethnic minority and white officers. The force was experiencing "major difficulties" in attempting to deal with cultural differences as a result of "bottom-up cultural norms which persons of different cultural backgrounds feel excluded from", it concluded.
The Assistant Chief Constable of Manchester, Dawn Copley, said the report contained a number of "discrepancies" over the authors' failure to include 550 additional investigations that would have redressed the balance.
"That said, we acknowledge that this report needed to be placed in the public domain because it raises a number of important issues and we do not shy away from that national discussion," she added.Reuse content