Brazilian police have raided the home of ex-President Luiz Inacio Lula da Silva as part of a fraud inquiry into the state oil company Petrobras.
The former president was being brought in for questioning, reports have said.
Officials say some 33 search warrants and 11 detention warrants are being carried out.
The long-running inquiry, known as Operation Car Wash, is probing accusations of corruption and money laundering at Petrobras.
Some 200 federal police agents were deployed in the states of Rio de Janeiro, Sao Paulo and Bahia.
Mr Lula's house in Sao Bernardo, near Sao Paulo, was raided early on Friday.
The headquarters of the former president's institute in Sao Paulo is also a target, as well as addresses linked to one of his sons, Fabio Luis.
One of the lines of inquiry is that construction companies targeted by the operation could have paid for the development of Mr Lula's ranch.
Dozens of executives and politicians have been arrested or are under investigation on suspicion of overcharging contracts with Petrobras and using part of the money to pay for bribes.
Mr Lula served two terms as president and left office in 2011.
