A Brazilian judge ordered the release of ex-billionaire Eike Batista late Saturday after he was detained for violating the terms of his house arrest, local media reported.
Appeals Court judge Simone Schreiber ruled that the detention of the magnate once considered Brazil's richest man "violated the Constitution... and the principle of presumption of innocence."
A Batista attorney cited by the G1 news site said that his client will be released on Sunday morning.
On Thursday the 62 year-old Batista, who had been under house arrest pending an appeal of a 30-year jail sentence, was arrested in Rio de Janeiro on suspicion of insider trading and money laundering, the news portal G1 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 later came under scrutiny by investigators in the vast "Car Wash" operation, which revealed mass corruption by public officials linked to oil company Petrobras.
In 2018, Batista was sentenced to 30 years in prison for corruption and money laundering.
Batista was found guilty of paying a $16.5 million bribe to former Rio governor of Sergio Cabral.