Besiktas are the latest Super Lig club to become embroiled in the Turkish match-fixing scandal following the arrest of their coach and deputy chairman.
Three Besiktas club officials, including coach Tayfur Havutcu, were taken into custody by Istanbul police early this morning, according to the nation's media.
Deputy chairman Serdar Adali and club security chief Ahmet Ates were also detained as part of the ongoing investigation into allegations of match-fixing last season.
Thursday's arrests follow those of Fenerbahce president Aziz Yildirim and Trabzonspor president Sadri Sener, with 26 people already awaiting trial.
Yildirim was among a group of people arrested two weeks ago following police raids across several cities.
Fenerbahce were crowned league champions last term, pipping Trabzonspor to the Super Lig title with a dramatic 4-3 win at Sivasspor on the final day.
Besiktas lifted the Turkish Cup after beating Buyuksehir in a penalty shoot-out.
Two Buyuksehir players were also arrested today, the Turkish media reported.
The Turkish Football Federation have said they will wait for the outcome of any legal action before launching their own investigation, with both Fenerbahce and Besiktas expected to remain in the draw for this season's Champions League and Europa League respectively.
UEFA announced on Tuesday they are monitoring the situation, but currently have no reason to ban any Turkish clubs from taking part in European competitions.
``Given the information received so far by UEFA there is nothing according to the UEFA statutes or regulations that leads UEFA to refuse entry to any of the clubs currently involved in the investigations in Turkey,'' said the governing body.
``In addition, every club participating in UEFA competition has provided UEFA with a written guarantee that they have not been involved in match-fixing activities.''