A federal judge in Brazil has sentenced a former presidential chief of staff to more than 20 years in prison for involvement in a massive corruption-kickback scheme at state-owned oil company Petrobras.

Judge Sergio Moro sentenced Jose Dirceu to 23 years and three months in prison. Wednesday's sentence can be appealed.

Moro is presiding over the Petrobras investigation that has ensnared some of Brazil's richest businessmen and top public figures from across the political spectrum.

Prosecutors say that more than $2 billion was paid in bribes and other funds by Brazil's biggest construction and engineering firms in exchange for inflated Petrobras contracts.

Dirceu is the most senior member of the Workers' Party to be arrested in connection with the case. He served under ex-President Luiz Inacio Lula da Silva.