A US federal court has ruled against Petrobras in its attempt to overturn a $622m arbitration award in favour of Vantage Drilling in a fight that centred on ­alleged bribery by Taiwanese shipowner Nobu Su.

District judge Alfred Bennett rejected the Brazilian state oil company’s motion to vacate the award, ruling Petrobras got a fair arbitration process.

“Although Petrobras’ briefing discusses at great length the iniquity of the alleged bribery scheme [that led to the Vantage contract], Petrobras’ arguments concerning the merits of the dispute are irrelevant to the court’s determination,” Bennett wrote.