A former director of Brazilian oil giant Petrobras who has accused dozens of politicians of taking kickbacks allegedly pocketed one himself for the purchase of a US refinery, local media reported.
Paulo Roberto Costa, currently in custody for money laundering, told police and justice ministry officials probing his allegations that he took 1.5 million reais ($636,000) as part of a deal to buy the Texas-based refinery, Globo television reported late Thursday.
Costa is at the heart of a corruption scandal that has made waves as Brazil approaches an October 5 election and has left President Dilma Rousseff fighting to fend off a challenge by former party ally Marina Silva.  
With Rousseff board chair at the time, Petrobras in 2006 approved the purchase of a 50 percent stake in the Pasadena facility from Belgian firm Astra Oil in a $370 million deal.
Astra had only a year earlier bought the entire site for $42 million.
In 2008, Petrobras ended up having to buy the other 50 percent after losing a legal battle.
The overall purchase ultimately cost the Brazilian firm $1.2 billion.
As part of a plea bargain bid to reduce a potential 40-year jail term, Costa told police about what he claims was a massive system of kickbacks benefiting some 50 politicians, most belonging to Rousseff's Workers Party and coalition allies.
The accused have denied the allegations.
The corruption controversy comes as Rousseff stands neck and neck with Silva in opinion polls.