Maria das Gra?as Foster is no average Brazilian executive. For a start, the chief executive of Petrobras is a woman — in fact, the first woman to lead an oil major. Nor was she born into a life of privilege but raised in one of Rio de Janeiro’s most dangerous slums. After collecting scrap metal for cash as a child, she joined Petrobras as an intern in 1978 and accumulated an encyclopedic knowledge of Brazil’s state-controlled oil producer that would put any boss to shame.

It is a remarkable career path but one that looks likely to end in a sadly familiar way by Latin American standards: with a corruption scandal. Over the past few months, Petrobras has become engulfed in the largest bribery and kickback investigation in Brazil’s history. Prosecutors believe that for much of the past decade, Petrobras executives conspired with Brazil’s largest construction firms to inflate the oil company’s contracts, stealing billions of dollars to fund lavish lifestyles, pay bribes and funnel money to politicians, largely from the ruling Workers’ party.

While Ms Gra?as Foster has not been accused of involvement in the scheme, the straight-talking 61-year-old has repeatedly offered her resignation to President Dilma Rousseff. “The president thought I should stay,” she told reporters bluntly in December. The reality, analysts say, is that no sane executive would be willing to take over the company in its current uncertain state.