Brazil's Federal Police on Wednesday launched the latest stage of a sweeping investigation into corruption at state-controlled firms, with six arrests and 15 search warrants issued in the states of Sao Paulo and Santa Catarina.
The warrants in the so-called "Operation Carwash" probe involve the suspected use of offshore companies and real estate transactions to launder money from bribery, graft and other offenses, police said in a statement.
According to TV Globo, raids were being conducted in Sao Bernardo do Campo, the political stronghold of former Brazilian President Luiz Inácio Lula da Silva, whose Workers' Party is involved in the probe.
Engineering firm Grupo OAS SA and cooperative bank Bancoop were among the targets of Wednesday's raids, the channel said, without saying how it obtained the information.
Dozens of executives and politicians have been arrested or are under investigation on suspicion of overcharging Petrobras and other state firms on contracts and using part of the proceeds to bribe members of President Dilma Rousseff's ruling coalition.
Around 80 police were involved in the latest raids, code-named "Triple X," according to the statement. They were collecting evidence of crimes including corruption, fraud, money-laundering and illegal foreign-currency market offenses.
In addition to the six arrests, two people were to be taken to police headquarters in the southern city of Curitiba for questioning, the statement added.
