Portuguese champions FC Porto have been formally accused of fixing two domestic fixtures in the 2003-04 season.
The games in question, against Estrela da Amadora and Beira Mar, came in the same year ex-Chelsea boss Jose Mourinho led Porto to Champions League glory.
"We've been notified by the Portuguese league (LPFP) of the accusations and investigations," said a club statement.
The club have been given five days by the LPFP to submit a written response to the allegations.
Porto beat Estrela da Amadora 2-0, while the match at Beira ended in a goalless draw.
Mourinho was not mentioned in the league's report, and Portuguese football journalist Alberto da Silva said the allegations were unlikely to involve the former Chelsea boss.
"It would not have anything to do with him," Da Silva told BBC Radio 5 Live.
Porto won their domestic title in the 2003-04 title, beating runners-up Benfica by eight points.
If found guilty, Porto could face a range of punishments, including a points deduction, relegation and fines.
Club president Jorge Pinto da Costa is to go to trial in a civil lawsuit by Porto prosecutors after he was accused of bribing the referee of the Beira Mar v Porto game.
~RS~q~RS~~RS~z~RS~22~RS~)