Last week, prosecutors ordered the detention of 46 people, including players, club presidents, commentators and a referee, over insider betting in Turkey's professional leagues.
State-run Anadolu news agency said on Tuesday that among those detained last week Galatasaray's Metehan Baltaci, Fenerbahce's Mert Hakan Yandas and former Adana Demirspor president Murat Sancak were now formally arrested.
"For years, the problems of Turkish football have been swept under the carpet," Turkish Football Federation Chairman Ibrahim Haciosmanoglu told a press conference.
He indicated that the federation's investigation could widen once it has received data from Turkey's state-run sports betting organisation Spor Toto regarding match observers, coaches, managers and others involved in football.
At a hearing on Monday, Baltaci told the court that he had placed bets on a few matches when he was a youth team player and had not done so after he joined the Galatasaray first team, according to Anadolu news agency.
Fenerbahce's Yandas was cited by Sabah newspaper as saying in his court testimony that he denied involvement in gambling on matches.
Sancak told the court he did not have a gambling account and had never placed a bet on matches, Cumhuriyet newspaper said.
Representatives of the two players and the former club official could not immediately be reached for comment.
Last month, Turkey's football federation suspended 149 referees and assistants after an investigation found that officials in the professional leagues were betting on games.
The net then widened with the arrest of eight people and the suspension of 1,024 players from all leagues, on whom the federation (TFF) imposed bans.
A trial date has not yet been set.
