Rudy Narayan, 58, of the group Civil Rights UK, is expected to be at the centre of a police investigation into whether the remarks incited a riot.
Standing on a wall outside the Brixton police headquarters he told the crowd on Wednesday evening: "The Brixton police are killers and they will not understand what they have done until one of them has been killed."
He said later that stood by his remarks and had no regrets. He added: "If a policeman is killed because he is behaving badly and someone is acting in self- defence I will not fret."
Before the rally the civil rights group published a press release that called for all the officers involved in the arrest of Wayne Douglas, the black man who died at Brixton police station, to be charged with murder.
Mr Narayan said yesterday: "I can't be responsible for what happened because the police started all the violence. There wasn't a problem until they marched on the black people and assaulted them."
He went on to describe Brixton police acting like "Nazis". He said the police community liaison committee were "house niggers who have been hand- chosen to tow the line".
Asked whether he thought he comments were irresponsible, he said: "I just tell it like it is."
A thorn in the side of the legal establishment for years, Mr Narayan retired briefly to his native Guyana in 1991 before returning to Britain.
A vigorous champion of black rights, he practised at the English Bar for 22 years. He was suspended from practice three times by the Bar Disciplinary Tribunal, most recently last year.
In his suspension for two years in 1988, over his conduct during the trials of two Rastafarians at Birmingham Crown Court, he told the tribunal that its all-white membership would "do credit to the Ku Klux Klan".Reuse content