Porto have been deducted six points by Portuguese football authorities for attempting to fix league matches.
The league's disciplinary committee ruled that Porto tried to bribe referees in two matches in the 2003/04 season, and, as well as the points deduction, have been fined €150,000 (£119,000) and barred chairman Jorge Pinto da Costa from the bench during matches for two years.
The league's disciplinary committee has also relegated Boavista to the second division and fined the club €180,000 (£143,500) after being found guilty of trying to coerce referees in three games in the 2003/04 season.
The club's chairman at the time, Joao Loureiro, was suspended for four years and fined €25,000 (£19,000).
Leiria, also a top-flight club but unable to avoid relegation this year, were found guilty of trying to bribe match officials the same season and was docked three points while fined €40,000 (£31,000). The club's chairman was suspended for one year.
Five referees have also been suspended for up to six years after being found guilty of corruption.
The sanctions are to take effect within three working days unless appeals were lodged. All three clubs denied the charges.
The points deduction will not prevent Porto from lifting their third consecutive league title, as the club will still maintain a 14-point lead going into Sunday's final fixtures.
The committee's president Ricardo Costa said officials questioned 85 people during the investigation and compiled a case file containing almost 1,000 pages.
He said in a televised press conference: "These decisions were unanimous. Five people agreed with the penalties to be applied."

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Paper review - 10th February
Chelsea v Arsenal
Birmingham v Wolves
Portsmouth v Sunderland - 1st Half
Wigan v Stoke - 2nd Half
Wigan v Stoke - 1st Half
Fulham v Burnley - 2nd Half
| Time | Fixture |
|---|---|
| Wednesday 10th February | |
| Barclays Premier League | |
| 19:45 | Arsenal vs Liverpool |
| 19:45 | Aston Villa vs Man Utd |
| 19:45 | West Ham vs Birmingham |
| 19:45 | Wolverhampton vs Tottenham |
| 20:00 | Blackburn vs Hull |
| 20:00 | Everton vs Chelsea |
| Tuesday 16th February | |
| Barclays Premier League | |
| 19:45 | Stoke vs Man City |
| Wednesday 17th February | |
| Barclays Premier League | |
| 20:00 | Wigan vs Bolton |
| Saturday 20th February | |
| Barclays Premier League | |
| 12:45 | Everton vs Man Utd |
| 15:00 | Arsenal vs Sunderland |
| 15:00 | West Ham vs Hull |
| 15:00 | Wolverhampton vs Chelsea |
| 17:30 | Portsmouth vs Stoke |
| Sunday 21st February | |
| Barclays Premier League | |
| 14:00 | Aston Villa vs Burnley |
| 15:00 | Fulham vs Birmingham |
| 15:00 | Man City vs Liverpool |
| 16:15 | Wigan vs Tottenham |
| Monday 22nd February | |
| Barclays Premier League | |
| 20:00 | Blackburn vs Bolton |
| Tuesday 23rd February | |
| Barclays Premier League | |
| 20:00 | Man Utd vs West Ham |
| Saturday 27th February | |
| Barclays Premier League | |
| 12:45 | Chelsea vs Man City |
| Time | Result |
|---|---|
| Tuesday 9th February | |
| Barclays Premier League | |
| Man City 2 - 0 Bolton | |
| Wigan 1 - 1 Stoke | |
| Portsmouth 1 - 1 Sunderland | |
| Fulham 3 - 0 Burnley | |
| Sunday 7th February | |
| Barclays Premier League | |
| Birmingham 2 - 1 Wolverhampton | |
| Chelsea 2 - 0 Arsenal | |
| Saturday 6th February | |
| Barclays Premier League | |
| Liverpool 1 - 0 Everton | |
| Hull 2 - 1 Man City | |
| Stoke 3 - 0 Blackburn | |
| Bolton 0 - 0 Fulham | |
| Sunderland 1 - 1 Wigan | |
| Man Utd 5 - 0 Portsmouth | |
| Burnley 2 - 1 West Ham | |
| Tottenham 0 - 0 Aston Villa | |
| Wednesday 3rd February | |
| Barclays Premier League | |
| Fulham 1 - 0 Portsmouth | |
| Tuesday 2nd February | |
| Barclays Premier League | |
| Hull 1 - 1 Chelsea | |
| Monday 1st February | |
| Barclays Premier League | |
| Sunderland 0 - 0 Stoke | |
| Sunday 31st January | |
| Barclays Premier League | |
| Man City 2 - 0 Portsmouth | |
| Arsenal 1 - 3 Man Utd | |
| Saturday 30th January | |
| Barclays Premier League | |
| Birmingham 1 - 1 Tottenham | |
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