RIO DE JANEIRO, Sept. 22 (Xinhua) -- Brazil's former Finance Minister Guido Mantega was arrested Thursday morning in connection with an ongoing investigation into a large corruption scheme at state oil giant Petrobras, but was released hours later due to his wife's illness.
Federal Judge Sergio Moro revoked the temporary arrest order, saying he had been unaware Mantega's wife was scheduled for surgery "due to a serious illness," said the national public news agency Agencia Brasil.
Moro found out about the wife's health condition when officials tracked Mantega down at a hospital in Sao Paulo after failing to arrest him at home.
Moro said there was no more need to arrest Mantega. All pertinent documents in his possession had been seized by police during a search and seizure of his residence, so he could not tamper with evidence, said the agency.
This phase of the investigation, called the X Files, is centered on possible kickbacks from Petrobras contracts granted to a construction consortium for the building of two oil platforms.
Prosecutors said Mantega asked for 5 million reals (about 1.5 million U.S. dollars) in kickbacks to pay off the campaign debts of the Workers' Party (PT), which was in power up to May.
Eike Batista, a former executive at the consortium, has testified that Mantega, who was head of Petrobras' board of directors at the time, asked for the funds at a meeting in November 2012. But Batista denied it was a kickback for securing contracts.
The PT called the arrest "deplorable", and a "political spectacle" designed only "to attack the Workers' Party."
In the lead up to local elections on Oct. 2, prosecutors were going after party leaders, including former President Luis Inacio Lula da Silva "with no evidence," the PT noted.
Mantega served as finance minister from March 2006, at the start of Lula's second term, to December 2014, during Former President Dilma Rousseff's second term.
Lula was accused of money laundering and corruption in connection with the Petrobras investigation, or Operation Car Wash.
Rousseff was impeached for breaking fiscal responsibility laws in her management of the federal budget, which was unrelated to Operation Car Wash.