BRASÍLIA - A Brazilian Supreme Court justice Thursday suspended powerful Lower House speaker Eduardo Cunha Thursday for obstructing efforts to investigate him as part of the Petrobras corruption scandal engulfing the country, a judicial source said.

Cunha, a key opponent of President Dilma Rousseff and architect of impeachment proceedings against her, "used his office for his own illicit ends to prevent the success of investigations against him," prosecutors said in asking the court to take action.

In March, the Supreme Court voted to put Cunha on trial, accusing him of taking $5 million in bribes as part of a vast embezzlement and bribery network centered on state oil giant oil Petrobras.

Cunha, who rejects the charges, is also being investigated by the congressional ethics committee over allegedly lying to Congress about possessing secret Swiss bank accounts.

But the speaker - who under Brazil's constitution is third in line to the presidency - had kept ahead of his own enemies and remained the go-to man in the push against the president.

Senators will vote next week on whether to open an impeachment trial against Rousseff.

Judge Teori Zavaski, in his ruling seen by AFP, said Cunha did not meet the requirements to exercise his role as speaker and was even less qualified to fill in for Rousseff.

Rousseff has referred to Cunha as one of "two leaders of the coup" she says is unfolding against her.

The suspension comes at a time of deep political and economic crisis in the South American country, which will host the Olympic Games in August.