Brasilia, Jan 20 (IANS): Brazil's President Michel Temer has mourned the death of Supreme Court judge overseeing the Petrobras scam, who was killed in a plane crash, a media report said on Friday.

Temer declared three days of national mourning in Brazil over Justice Teori Zavascki's death, Xinhua news agency reported.

Zavascki was in charge of the probe known as Lava Jato, or Car Wash, the massive kickback and corruption scheme involving many of Brazil's biggest companies, including state-run oil giant Petrobras.

Zavascki has played a crucial role in the inquiry that has implicated scores of politicians - including the current and former Presidents Michel Temer and Luiz Inacio Lula da Silva and several dozen other prominent politicians - and resulted in the jailing of the former head of the lower house of Congress, Eduardo Cunha.

"He was a good man and a source of pride for all Brazilians," Temer said.

"I join all Brazilians to regret the passing of a public man distinguished by his impeccable trajectory in defense of the law and justice," he added.

Former President Dilma Rousseff, who appointed Zavascki to the Supreme Court in 2012, also issued a statement mourning his death.

The Brazilian media reports said Zavascki had received threats in the past year, one of them he confirmed in June 2016, linked to his job investigating the corruption scheme involving government contracts with the private sector, especially Brazil's oil giant Petrobras.

His death in the Thursday plane crash came several days after media reported he was about to admit key testimonies implicating high-profile politicians.

At least three were killed out of the four people on board the plane flying from Sao Paulo to Paraty, about 260 km west of the city of Rio, according to Brazilian media.

The plane crashed into the sea during poor weather conditions shortly before landing in Paraty.

So far, there has been no evidence of foul play found in the crash.