 On 20 April 2004, the Apito Dourado operation was triggered, leading to the arrest of 16 people, including club officials and referees.Among them were the then Portuguese League for Professional Football President and Mayor of Gondomar, Valentim Loureiro, the then Chairman of the Refereeing Board, José António Pinto de Sousa, and the then chairman of Gondomar S.C., José Luís Oliveira.On 2 December, the Judiciary Police was supposed to conduct a search at Pinto da Costa's home, but the Chairman of FC Porto had allegedly been previously informed by a source in the Judiciary Police, clearing the site beforehand.