Turkish prosecutors have questioned Emre Belozoglu, the captain of the Turkish national team, in a match-fixing probe that also involves his club Fenerbahce.
Belozoglu says he was released without charges on Tuesday. He refused to answer questions, saying he was tired and had "spoken enough'' during his testimony.
According to Turkish publication Zamen, the former Newcastle and Inter Milan midfielder was forced to answer questions on allegations that he sent a series of text messages to Ankaragucu defender Kagan Soylemezgiller before the two clubs met in the last match of the season in May.
Prosecutors also questioned Fenerbahce manager Ekrem Okumus; a sports commentator as well as Sinan Engin, a former Besiktas player and director of football.
Fenerbahce could lose its league title and be relegated. The Turkish Football Federation pushed back the start of the season for more than a month until September 9 because of the inquiry.
Last month, an Istanbul court jailed Fenerbahce chairman Aziz Yildirim, pending trial on charges of match-fixing as part of an investigation that could result in the club being stripped of their title as league champions.
Yildirim joined over 30 others already remanded in custody after police raids, prompted by evidence of manipulation in 19 matches, which Turkey's prime minister said has stained Turkey's image.