RIO DE JANEIRO — A Supreme Court judge ruled Friday that Brazil's federal police may question former President Luiz Inacio Lula da Silva as a witness in their investigation of a kickback scandal that has engulfed the state-owned oil company Petrobras.
The ruling came on a request filed by investigators Sept. 11 who said they wanted to question Silva about possible involvement in the scheme. Under Brazilian law, all federal politicians and some at other levels can be investigated only if the Supreme Court approves the inquiry.
Prosecutors allege that over $2 billion was paid in bribes by businessmen to obtain Petrobras contracts, projects that then subsequently ballooned in costs. Investigators also have said that some of the money made its way to the governing Workers' Party.
Justice Teori Zavascki said in his decision that Silva is to be heard as an "informant."
The Lula Institute, a foundation run by the former president, said he had no comment on the ruling.
Although Silva is no longer in office, legal analysts have said the Supreme Court needed to approve him being questioned because the investigation involves active politicians.
More than 50 people, including the head of the Chamber of Deputies, other deputies, senators and other top political figures, have been charged in the case or are under investigation.
President Dilma Rousseff was chairwoman of the Petrobras board during the period of the alleged scheme but no accusations have been made against her. Both she and Silva have denied any wrongdoing.
Silva is a two-term president who left office in 2011 with an approval rating of 86 percent and who has made it clear he could run again for the presidency in 2018 as the candidate of Workers' Party, which he helped found.
Silva's former chief of staff, Jose Dirceu, was charged in September with corruption, racketeering and money laundering in connection with the Petrobras investigation.
Separately from the Petrobras case, prosecutors said in July that they had enough evidence to warrant a full investigation of Silva's alleged overseas lobbying for Brazil's biggest builder, Odebrecht, whose CEO is now in jail because of his alleged involvement in the Petrobras case.