Eike Batista, once considered the richest man in Brazil, was released from prison Sunday and moved to house arrest, authorities in Rio de Janeiro state said.
Accused of corruption in a case related to the massive bribery and kickback scandal at state oil giant Petrobras, Batista was approved for release on Friday from Bangu prison by Brazil's supreme court.
"He left the prison this morning, without incident, and continues under house arrest," an adviser to the state's secretary of penitentiary affairs said.
An emblem of Brazil's boom years, Batista amassed a fortune with investments in mining and oil that in 2012 put him in seventh place on Forbes's list of the world's wealthiest.
But by 2013 a downturn in the commodities market wiped out a fortune that had been estimated at $30 billion.
He was arrested on January 30 upon arrival on a flight from New York, on suspicion of having paid former Rio governor Sergio Cabral $16.5 million, allegedly through the fictitious sale of a gold mine.
Cabral had been arrested in November on charges of heading a criminal enterprise that allegedly diverted tens of millions of dollars from public works contracts.
In authorizing Batista's release to house arrest, Supreme Court Justice Gilmar Mendes ruled that "the fact that he was accused of serious crimes -- corruption and money laundering -- in itself cannot serve as the sole and exclusive basis for maintaining his preventive imprisonment."
After his arrest, Batista was put in a prison for common criminals.
Because he was not a university graduate, he was ineligible for special prison conditions that Brazilian law provides for inmates with higher levels of education.