Recep Tayyip Erdogan, an avid Fenerbahce supporter, said Wednesday he backed a “thorough” probe into the scandal which was tarnishing Turkey’s image.

Turkish authorities have detained some 60 people, including Fenerbahce’s president and other clubs’ officials and players, suspected of alleged match-fixing in the Turkish league last season.

The state-run Anatolia news agency says prosecutors are questioning 25 of the suspects Wednesday.

Seven other suspects were formally arrested after questioning Tuesday while 11 were released from jail.