Brazil’s Supreme Court said Tuesday the country’s top prosecutor is seeking permission to investigate former President Luiz Inacio Lula da Silva for alleged connections to political corruption at Petrobras, the state-owned oil company that has long been a key funder of government policies.

Attorney General Rodrigo Janot is also seeking the court’s permission to probe Political Affairs Minister Ricardo Berzoini, Social Communications Minister Edinho Silva and President Dilma Rousseff’s office manager, Jaques Wagner, the Associated Press reported.

The news comes a day after Janot asked the court to open a case against opposition Sen. Aecio Neves, who narrowly lost to Rousseff in the country’s 2014 presidential election, as well another lawmaker from Rousseff’s ruling Workers Party (known by its local acronym PT) and an administrative judge.

A little over a year into her second term, Rousseff is fighting increasing calls for her impeachment over a sprawling scandal involving Petróleo Brasileiro S.A. (commonly called Petrobras), one of Latin America’s largest companies that’s closely held by the Brazilian government.

The company has been embroiled in a massive scandal in which company officials and politicians overcharged for projects and then laundering and pocketing the proceeds. Many politicians either in the PT or previously aligned to it are believed to have taken hush money or used illicit funds for their campaigns.

Lula was president during much of the time the alleged corruption took place. Rousseff was his energy minister and head of the company during his administration. In March Rousseff tried to shield Lula from prosecution by naming him her chief of staff. A judge intervened to block the appointment.

Under Brazilian law, Cabinet ministers can be tried only in a special forum of the Supreme Court. Many of the Supreme Court justices were appointed by Lula or Rousseff.

Rousseff is not being investigated for taking bribes, but she’s awaiting a Senate impeachment vote linked to charges she broke budgetary laws.