The former director of the international division at Brazil's scandal-plagued state oil company, Petrobras, was sentenced Monday to 12 years and two months in prison for corruption and money laundering.

Jorge Zelada was convicted of taking bribes in a massive pay-to-play scheme that has upended Brazilian politics and cost the country's largest company more than $2 billion.

Judge Sergio Moro found Zelada and accomplices took nearly $31 million in bribes to grant a $1.8-billion drillship rental contract to US oil rig company Vantage Drilling Corporation.

"The contract was illicitly steered toward Vantage Drilling Corporation in return for the payment (of the bribe)," the judge said in his ruling.

Brazil has seized nearly $12 million from bank accounts in Monaco held by companies linked to Zelada, who headed Petrobras's international division from 2008 to 2012.

Investigators say he also stashed money in Swiss accounts.

Prosecutors say Petrobras, long a pillar of the world's seventh largest economy, was at the center of a sprawling embezzlement, bribes and kickbacks scheme in collusion with construction companies and political parties, including the ruling Workers' Party.

The chief executives of construction giants Odebrecht and Andrade Gutierrez are among other high-ranking business figures already snared, along with a former Workers' Party treasurer.

Dozens of politicians are under investigation, including lawmakers, governors and cabinet ministers.

The sweeping corruption probe, called Operation Carwash, has uncovered a network of at least 16 companies that "bought" lucrative Petrobras contracts with bribes of between one and three percent of the total value, prosecutors say.

The scandal and the slide in oil prices have been catastrophic for Petrobras, which was downgraded to junk status by ratings agency Moody's in December and has slashed its planned investments and production targets for 2016.