(BBC) A prominent Brazilian Supreme Court judge has died in a plane crash.
Two other bodies were found at the crash site in the sea near Paraty, some 250km (160 miles) south of Rio de Janeiro.
Teori Zavascki, 68, was overseeing a massive corruption investigation at the state oil company, Petrobras.
Dozens of politicians have been arrested as part of the inquiry, known as Operation Car Wash, over the past two years.
Prosecutors say politicians were paid vast amounts in exchange for granting lucrative contracts to private companies that had overcharged Petrobras.
Mr Zavascki’s plane crashed into the sea in heavy rain.
“The curve the pilot was making seemed too severe,” one eyewitness, Lauro Koehler told local media.
“But the plane kept curving, to the point that my wife screamed, ‘It’s going to crash!’ Then the plane dropped into the sea.”
President Michel Temer has declared three days of national mourning following Mr Zavascki’s death, calling him “a good man, and a (symbol of) pride for all Brazilians”.
Mr Zavascki had been investigating executives from Odebrecht, Latin America’s largest construction firm.
Odebrecht has admitted to paying $1bn in bribes to obtain in contracts in 12 different countries.
The testimonies are expected to provide evidence against powerful politicians in Brazil – including members of the current government of President Temer.
Huge loss: Analysis by Daniel Gallas, BBC News, Rio de Janeiro
In Brazil’s tumultuous times, where political divisions are running deep in virtually every institution, it is hard to find truly independent voices.
But Judge Teori Zavascki was arguably one such voice. The Petrobras investigation gained much credibility when he was appointed to oversee the case in the Supreme Court.
A few days from now, the court will start analysing the plea bargain deals struck with 77 executives from Odebrecht, a construction company that admitted corrupt deals with Petrobras.
This has the potential to be the most explosive moment in the long-running Petrobras case, as new revelations are expected to be made against top politicians.
Without Judge Zavascki at the helm of this process, Brazil’s Supreme Court will have an extra challenge in convincing the public it can resist pressure from the powerful.