Pinto da Costa allegedly tried to fix a match against league rivals Estrela da Amadora in January 2004 which his side won 2-0.

Retired referee Jacinto Paixao and his assistants Manuel Quadrado and Jose Chilrito have also been placed under judicial investigation along with club official Reinaldo Teles, and businessman Antonio Araujo.

Da Costa, president of FC Porto for the past 25 years, was charged for the first time in 2005 for three offences of active corruption and corrupt practices, but was released in October of that year.

The affair was filed because of lack of evidence but was reopened following new evidence acquired from telephone tapping and testimony from da Costa's ex-wife Carolina Salgado, who has written a book on the affair.

These latest judicial investigations are part of the operation codenamed "Golden whistle" which is still underway and is probing an alleged network of match-fixing in professional football in Portugal between 2001 and 2004.

The scandal broke in April 2004 and lead to 70 searches and the arrests of 16 sporting officials, of which most were referees suspected of match-fixing.

The 2004 Champions League winners, FC Porto won their 22nd league title last month.