The Brazilian Supreme Court on Wednesday accepted the appeals of a dozen former political and business leaders found guilty in the nation's biggest corruption trial, paving the way for new trials and dealing a blow to those who hailed the earlier convictions as a turning point against impunity.

The case involves a scheme that came to light in 2005 in which top aides to former President Luiz Inacio Lula da Silva created a scheme to pay off legislators so they would support the ruling Workers Party initiatives in Congress.

The guilty verdicts for 25 defendants last year were seen as a positive sign in a country where public service has been marred by corruption and impunity for centuries. On Wednesday, the 11-member court weighed a technical wrinkle in the case and decided in a 6-5 vote that defendants have the right to a new trial for the criminal counts for which they earlier received at least four not-guilty votes.

That means 12 defendants will get new trials, including Silva's former chief of staff Jose Dirceu and the former Workers Party president Jose Genoino for conspiracy, and Joao Cunha, the ex-leader of Brazil's lower house of Congress, for money laundering.