On 9 June 2010, a first instance São Paulo State court intervened in an ongoing arbitration proceeding. By means of a writ of mandamus (Mandado de Segurança), the court reviewed the arbitral tribunal's decision rejecting a party's request for production of additional engineering evidence. The state court issued an order to assure the production of engineering expert opinion before the arbitral tribunal. In a preliminary judgment by the São Paulo State Court of Appeals, the effect of this order was suspended on 22 June 2010.