The major nationwide investigation has plunged preparations for the new season into chaos less than a month before kick-off and could result in champions Fenerbahce being stripped of their title.
The detention of Trabzonspor's Sadri Sener in Istanbul came just hours after the chairman of Fenerbahce, Aziz Yildirim, was remanded in custody on charges of match-fixing and forming a criminal organisation.
Police were also taking a statement from the former Turkish Football Federation chairman Mahmut Ozgener after summoning him to police headquarters, media reports said. Initial reports said police had detained him.
Among others held on Monday were another former federation executive once responsible for the national team, Ankaragucu goalkeeper Serdar Kulbilge and a former executive of the Ankara club, media reports said. Police have yet to make a statement.
Shares in Fenerbahce tumbled on the Istanbul Stock Exchange last week on speculation it could be stripped of the title.
Shares in Trabzonspor, runners-up last season, rose last week on speculation they could be awarded the title but they fell 5.5 percent on Monday after the detention of their chairman. Fenerbahce shares dipped 2.8 percent.
Trabzonspor fans protested in the streets of the Black Sea town on Sunday, calling for the league title to be awarded to their club.
FENERBAHCE PROTESTS
Other Fenerbahce board members are also among the 26 people who have been remanded in custody after police raids a week ago, prompted by alleged evidence of result manipulation in 19 matches.
Among these matches was Fenerbahce's 4-3 victory over Sivasspor which clinched the title for them on the final day of the season, according to media reports.
Angry Fenerbahce supporters demonstrated in their thousands in streets near the club's stadium after the court ruling on Yildirim. The club won the league for a record 18th time last season.
Prime Minister Tayyip Erdogan has called on Fenerbahce fans to respect the judicial process and has said the match-fixing affair has stained Turkey's image.
Meanwhile, European football's governing body UEFA has set a deadline of July 15 for confirmation of the team taking part in the third Champions League qualifying round, which would normally be Trabzonspor as runners-up in the league.
Those already jailed pending trial include four Fenerbahce executives, the chairman of Sivasspor, the coach of Eskisehirspor, Sivasspor's goalkeeper and the former chairmen of Diyarbakirspor and Giresunspor.
