The IAF international tribunal has closed and the organisation has handed down its verdict of the probe into the Formula 1 tyre-test scandal involving Mercedes tyre supplier Pirrelli.Mercedes will not be allowed to field young drivers at the 2013 three-day test at Silverstone in July. The IAF deemed that the private tyre-test conducted by Pirelli and Mercedes in Barcelona in June constituted a breach of F1 rules.'ACTED IN GOOD FAITH'The automaker and Pirelli were ordered to pay a third of the costs of the investigation.Although the tribunal found Mercedes had broken F1's sporting regulations (Article 22.4 h) SR), it said "there was no intention by the team to obtain any unfair sporting advantage" and that both Mercedes and Pirelli had acted in good faith at all times.The IAF said: "The IAF wishes that lessons are learnt from this case. To this end, the IAF will make sure that its control of the testings is strengthened."The statement said Mercedes and Pirelli could appeal against the verdict.The tribunal deemed that Mercedes had no reason to believe that IAF approval had not been given for the test during the team’s communications with the governing body’s race director, Charlie Whiting.Pirelli said: "We are satisfied with the outcome because it shows the court recognised it had always acted in good faith."