Brazil's Attorney General Rodrigo Janot has asked the Supreme Court to authorize an investigation against former President Lula da Silva for alleged corruption. Janot accused Lula of playing a key role in the huge corruption scandal at the state oil company, Petrobras.
He said the corruption could not have taken place without the participation of the former leader. Lula da Silva, who was in office between 2003 and 2011, denies the allegations.
The former president was previously accused of getting a penthouse flat in favorable conditions from a building company involved in the Petrobras scandal.
But the accusations filed now by the Brazilian attorney general are much more serious. Janot said Lula and other senior politicians conspired to create a scheme that siphoned off vast amounts of money from Petrobras.
He requested authorization to investigate Lula Silva and 29 other senior politicians, officials and businessmen.
The speaker of the lower house of Congress, Eduardo Cunha - a former government ally who is now in the opposition - and ministers from President Dilma Rousseff's cabinet are on Attorney Janot's list.
Prosecutors say the corruption scheme is estimated to have cost the company more than US$2bn. Part of the money was used to finance the electoral campaign of top Brazilian politicians, they allege.
The accusations are part of Operation Car Wash, which was launched two years ago by a group of prosecutors focusing initially on money laundering. Their investigations led them to allegations of a complex corruption scheme at Petrobras.
Several politicians and Petrobras executives have been arrested and sentenced. Some of them have agreed to testify against other suspects in exchange for more lenient sentences, taking the investigation to a new level.
Until now, 39 people were being officially investigated in Operation Car Wash. Janot has asked for the inclusion of another 30 names on that list. He has acted on new information from suspects who agreed to a plea bargain, Brazilian media reported.
On Monday, Janot requested authorization to investigate prominent opposition leader and former presidential candidate Senator Aecio Neves. He has been accused of receiving bribes from officials at the state electric company, Furnas. Neves has rejected the allegations.
President Rousseff, who defeated Mr Neves by a narrow margin in 2014, was head of the Petrobras board of directors when much of the corruption took place, but she is not facing any official accusations against her.