Petrobras head meets Brazilian leader Rousseff, fueling speculation she will leave post

The embattled chief executive officer of Brazil's state-run oil company has held a meeting with President Dilma Rousseff, sparking speculation the executive will soon be forced from her post.

Investigators and prosecutors have been probing for months what they say is Brazil's biggest corruption scheme yet known, an alleged kickback scandal on billions worth of Petrobras contracts.

Rousseff's office denied reports Tuesday that Maria das Graca Foster, the CEO at Petrobras, was on her way out. Calls have come from business and political circles for the executive to be fired amid the investigation.

Brazil's main stock index cheered the meeting, sending shares to their biggest single-day gain in over a decade.

Prosecutors have already jailed several executives from Brazil's top engineering and construction firms, along with former executives at Petrobras.