The organisation which deals with police complaints in England and Wales on Friday announced a review into whether forces discriminate against ethnic minorities.
The Independent Office for Police Conduct (IOPC) said the probe, to begin in the coming months, will initially look into the use of stop and search powers and the use of force.
It comes amid growing scrutiny of police attitudes to black and ethnic minority (BAME) communities in Britain following the Black Lives Matter protests sparked by the death in US police custody of an unarmed black man, George Floyd.
The head of London's Metropolitan Police, Cressida Dick, this week apologised to British sprinter Bianca Williams for the "distress" caused when she and her partner were stopped by police. Nothing was found in the search.
"Evidence of disproportionality in the use of police powers has long been a concern which impacts on confidence in policing, particularly in the BAME communities," said IOPC director general Michael Lockwood.
"But even with the numbers and the statistics, particularly from stop and search data, we still need to better understand the causes and what can and should be done to address this."
Race discrimination will become a "thematic area of focus, to establish the trends and patterns which might help drive real change", he said.
Black people were more than eight times more likely to be stopped and searched than white people in 2016-17, according to a 2018 study by drugs charity Release and the London School of Economics.
Police forces currently deal with the majority of complaints where discrimination is alleged themselves, about 32,000 a year, according to the IOPC, but the watchdog will now take on more of these.
As well as looking at stop and search and use of force, the IOPC will review how forces treat allegations of hate crime against BAME communities and allegations that police do not treat BAME victims of crime, as victims.
In 1999, the Met Police were branded institutionally racist for their bungling of a high-profile racially motivated killing of a black teenager, Stephen Lawrence, six years earlier.
The report, and subsequent public outcry, led to an overhaul of the force.