Metropolitan Police officers were four times more likely to use force against black people compared with the white population, new figures have suggested.
Restraint techniques were also more likely to be used on black people, according to force records.
A serving officer told the BBC this was because police found black people “more threatening and aggressive”.
Scotland Yard said “the causes of disproportionality are not straight forward and easy to understand”.
Assistant Commissioner Nick Ephgrave told the BBC the police response could only be judged when taking into account “the types of crimes committed, the type of demographics of individuals involved in those crimes”.
The Met used force 159,000 times in 2019-20, with more than a third of incidents involving black people.
While force was used on white people more often, the rate of incidents was lower compared with the proportion of London’s population that was white, according to Greater London Authority estimates.
The Met Police are more likely to use force against black people than other ethnicities
A serving officer, who spoke to the BBC on condition of anonymity, said: “As far as they’re concerned black people are more aggressive.
“You should calm them down but instead they are keen to put hands on first because it’s flight or fight.
“Particularly with black men, if a black person is upset, saying ‘it’s hurting’, they say ‘it looks fine to me’.”
Restraint techniques and unarmed skills – which include wristlocks, strikes, take downs and groundpinning – are three times as likely to be used on black people than on white people, according to BBC analysis of Met Police data.
In 2019-20 the Met restrained 18 black people per 1,000 population on average. Five white people were restrained per 1,000 population.