BRAZILIAN police questioned former president Luiz Inacio Lula da Silva yesterday as part of a bribery investigation being used to target his successor’s government.

Two of Mr da Silva’s sons were also quizzed over the corruption scandal at state oil company Petrobras following a dawn raid on the family home, non-government organisation the Lula Institute and other properties.

Police said they were acting on 33 search and 11 arrest warrants in the Operation Carwash investigation.

Mr da Silva was taken to the federal police station at Sao Paulo’s Congonhas airport. Lula Institute spokesman Jose Chrispiniano said the questioning lasted almost four hours.

“No-one is exempt from investigation in this country,” said public prosecutor Carlos Fernando dos Santos Lima. “Anyone in Brazil is subject to be investigated when there are indications of a crime.”

But the institute said “nothing justified” the morning’s events and denied any wrongdoing on Mr da Silva’s behalf.

The arrest followed claims on Thursday by Senator Delcidio do Amaral from Mr da Silva’s Workers’ Party (PT) — himself under investigation and facing expulsion from the party — linking the former president to bribery.

Yesterday recently resigned justice minister Jose Eduardo Cardozo questioned Mr do Amaral’s credibility, saying: “He’s not someone who has excelled at telling the truth.”

Newspapers also reported that Mr do Amaral’s statements were part of testimony aimed at securing a plea bargain.

Clashes broke out between Mr da Silva’s supporters and opponents outside the former president’s flat in Sao Bernardo do Campo, while hundreds of people demonstrated at the airport.

Prosecutors claim some £1.5 billion was paid in bribes by businessmen to obtain Petrobras contracts, some of it ending up in PT coffers.

PT supporters insist that the true aim of the Petrobras investigation is to bring down the PT government of President Dilma Rousseff.

Party president Rui Falcao denounced the arrests as “a political spectacle that shows what the true character of this operation is.”

Late last month, Mr da Silva indicated that he may stand for president again “if necessary” when Ms Rousseff’s term ends in 2018, declaring that he had the “passion of a 30-year-old” for the job.