PARIS (AFP) - The United States is cursed with "Third World police" that has led to "almost state-sanctioned" killings of people from minority groups, one of the country's leading black writers said on Sunday (Sept 11).

Marlon James, who won the prestigious Man Booker Prize last year for his epic novel A Brief History of Seven Killings, told a literary festival in Paris that some officers thought themselves above the law, comparing them to death squads during the "dirty war" run by Argentina's military rulers in the 1970s.

"What people like me find alarming is there is almost state-sanctioned violence in America, particularly with the police," said the Jamaican-born novelist, who has lived in the US for more than two decades.

"America has developed a weird kind of Third World police, which horrifies people like me and my friends from Kenya or Nigeria.

"The whole idea that you are beyond the law you are serving and protecting, and that killing people will not have consequences, is something that we who migrated to America thought we had got away from," he told an audience at Festival America.

"This sort of unquestioned authority, straight up killing people is why Black Lives Matter happened," he added, referring to the protest movement that sprung up out of a series of high-profile police killings of black men.

"The way that kind of violence is protected... means it is state-sanctioned violence and that is no different to Argentina during the dirty war."

James, 45, whose parents were both police officers in Jamaica, said Americans had to look hard at themselves as well as at their police.

"I don't think it is something that Americans realise because it is mostly a minority that is victimised by it. We are naive in that we never pay attention to violence until it affects us.

"And that is a problem because when it finally does come to us nobody is going to be protecting us. It will end up endlessly repeating itself unless we stop it at some point," he warned.

James' virtuoso Man Booker-winning novel follows a group of people involved in the attempted assassination of the reggae legend Bob Marley in Kingston just before he was to appear at a political rally.

The ironically titled A Brief History of Seven Killings runs to nearly 700 pages, with the New York Times calling it "epic in every sense of that word: sweeping, mythic, over-the-top, colossal and dizzyingly complex".

The writer, who teaches literature at Macalester College in Saint Paul, Minnesota, was the first Caribbean writer to win one of literature's most prized awards since V.S. Naipaul in 1971.