Brazil’s anti-corruption obstacles continue to escalate, following the resignation this week of the federal government’s head of anti-corruption, amid a corruption probe unfolding against Brazilian state-owned oil company Petrobras.

Comptroller General Jorge Hage, who was appointed under Brazil’s former President Luiz Inacio Lula da Silva to head the comptroller’s office in 2006, announced his resignation on Dec. 8 during a news conference marking international Anti-Corruption Day. Hage said he gave Brazil’s current President Dilma Rousseff his resignation letter in November, after she won a second term in office.

Hage’s resignation comes as eight engineering and construction companies that held contracts with Petrobras face allegations that they took part in a widespread money-laundering scheme. The companies involved are Camargo Correa, Engevix, Galvão Engenharia, IESA, Mendes Junior, Grupo OAS, Queiroz Galvão and UTC-Constran, according to the Buenos Aires Herald.

Brazilian prosecutors also are preparing to indict eleven executives from those companies believed to be involved in the scheme, the Buenos Aires Herald reports.

Since March, Petrobras has been rocked by allegations made by Paulo Roberto Costa, former head of refining, that executives of the state-owned oil company engaged in a money-laundering and bribery scheme whereby billions of dollars were shaved off the value of contracts in the form of kickbacks paid back to Petrobras executives and politicians.

During the press conference, Hage said that a budget cut of nearly $3 million in 2014 has made it difficult for the comptroller’s office to fulfill its mission, with the Petrobras scandal adding to its woes. Specifically, the budget cut forced the comptroller's office to shift its personnel to the energy and petroleum sector to respond to the Petrobras scandal, he said.

The bribery allegations against Petrobras are also being investigated by the Department of Justice and the Securities and Exchange Commission for potential violations of the Foreign Corrupt Practices Act.