Brazil's federal audit court on Wednesday ordered a freeze of former President Dilma Rousseff's assets as well as those of Jose Sergio Gabrielli, ex-head of state-run oil company Petrobras, over a $580 million loss in the 2006 purchase of a Texas refinery.

The order also covered former Finance Minister Antonio Palocci and three members of the board of directors Petrobras that approved the controversial purchase.

The court, known as the TCU, said it detected "irregularities" in the purchase of the refinery in Pasadena, Texas, a move that it considered made no business sense.