Seventy-five police officers in the Brazilian city of Rio de Janeiro have been arrested as part of a probe into drug trafficking and organised crime.
The officers arrested were said to come from Rio's toughest areas
More than 500 police were deployed to arrest the officers, members of Rio's heavily-armed paramilitary police.
Brazilian police are regularly accused of corruption and brutality, with two recent reports suggesting widespread involvement with drugs and firearms.
There was no indication of what charges the officers might face.
The head of Rio's elite paramilitary police said the operation was the biggest of its kind against serving officers.
They are thought to have profited from drug trafficking and other forms of organised crime.
Some officers are suspected of selling police uniforms on to criminals.
Most of those arrested were said to be from the city's most violent and crime-ridden districts.
Some 350 Rio police officers, backed by 200 federal police flown in from the capital, Brasilia, detained the suspects as they arrived for work on Friday morning
State police commander Hudson Aguiar said Rio's police force was committed to rooting out rogue elements.
"We will continue to expel those who don't honour their commitment to society," he said.
Rio's powerful drug gangs have long been thought to have contacts, links and even direct control, over elements of the city's police force.
But arrests are rare and prosecutions rarer still.
Nevertheless, a survey of guns seized from criminals in Rio revealed that almost 20% carried weapons that once belonged to police officers or soldiers.
Another study revealed that police routinely extort money from those involved with drug gangs, confirming suggestions that some of those paid to fight crime in Brazil are in fact profiting from it, says the BBC's Steve Kingstone in Brazil.