ISTANBUL (AP) — Prosecutors in Istanbul on Friday issued arrest warrants for dozens of soccer players and officials in relation to a betting scandal that has shaken Turkey.

Among those detained in early morning police raids were players from Turkey’s leading clubs: Mert Hakan Yandas of Fenerbahce and Metehan Baltaci of national champions Galatasaray.

The Turkish Football Federation said in October that it was investigating more than 150 referees in professional leagues for allegedly betting on soccer matches.

The probe soon expanded to include players, administrators, TV commentators and others in the sport. Last month more than 100 professional players, including 25 from the top-tier league, were given temporarily bans.

The Istanbul Chief Public Prosecutor’s Office issued warrants for 46 suspects on Friday. The office said Friday morning that 35 had already been detained, including the chair of Ankaraspor, Antalyaspor’s vice-chair and Adana Demirspor’s former chair.

Former referee and commentator Ahmet Cakar and current referee Zorbay Kucuk were also arrested, news agency DHA reported.

In a statement, prosecutors said Baltaci, who previously played for national youth sides, had been found to have placed bets on his own team’s games. Yandas allegedly placed his bets through someone else.

Seven people, including Cakar and Kucuk, were arrested after “suspicious financial transactions” were found in their bank accounts.

All the suspects were detained under a law to prevent disorder in sport, the statement added. The law criminalizes the manipulation of sports competitions and carries a sentence of one to three years’ imprisonment, which can be increased if the offense is connected to betting markets, involves officials or affects professional leagues.

Under world and European soccer regulations, players, referees and club officials are prohibited from betting on games at any level.

The Turkish Football Federation has vowed to clean up the sport, with president Ibrahim Haciosmanoglu saying he would protect it from “scandal, decay and corrupt relationships.”