Lula is one of seven accused of hindering the probe into the controversy.

Operation Car Wash began as a money laundering investigation, but prosecutors uncovered a maze of corruption at the state run oil company.

Lula and his co-accused are charged with attempting to prevent former Petrobras director Nestor Cervero from testifying in a plea bargain deal.

Cervero has been jailed as the mastermind of the scam, estimated to have cost the company some $2bn.

Lula, who held office from 2003 to 2011 has denied any wrongdoing. (Euronews)