European champions Porto president questioned in corruption probe

FC Porto president Jorge Nuno Pinto da Costa appeared before a court in Portugal to be questioned as part of an ongoing probe into sports corruption which has already led to the arrest of 21 people

FC Porto president Jorge Nuno Pinto da Costa appeared before a court in northern Portugal to be questioned as part of an ongoing probe into sports corruption which has already led to the arrest of 21 people, local media reported.

Police on Thursday raided the offices of the defending European champions as well as the home in the northern city of Oporto of its president and issued a summons for Pinto da Costa to give testimony as part of their probe.

Judiciary police also detained four leading referees on Thursday as well as a FIFA agent in Oporto, the northern city of Braga and Evora in the south.

One was questioned and released, while the other four were held in prison overnight.

Among those detained was referee Augusto Duarte, 38, who was scheduled to rule over Sunday's first league match between Academica and Sporting Lisbon.

The five arrests were a follow-up to the so-called "Operation Golden Whistle" launched in April in which police arrested 16 people, including president of the Portuguese Professional Football League, Valentim Loureiro, and the head of the country's referees' council, Antonio Pinto de Sousa.

Both men have had their mandates suspended.

Police also arrested nine lower-ranking referees as part of their sweeps carried out in April.

The detentions were made after a 15-month investigation, which included wiretaps of telephone calls, that police said had uncovered strong indications of sports corruption and influence trafficking involving referees

The questioning of Pinto da Costa comes as Porto prepares to face Chelsea in the Champions League on Wednesday.