Citing a statement from the prosecutor's office, NTV said 24 of the 29 suspects were detained, including former Galatasaray executive Erden Timur.
Timur and Galatasaray were not immediately available for comment.
Four others were sill being sought, while another suspect was already in jail, the statement added.
NTV said 14 of the suspects were players in Turkish leagues, without naming them, while six were being sought for betting on a Super Lig match between Kasimpasa and Samsunspor in October 2024.
Turkey's football federation suspended 149 referees and assistants last month over betting on games. The net widened with the arrest of eight more people, including the chairman of a top-tier club, and the suspension of 1,024 players from all leagues, with the federation also imposing bans.
Earlier this month, prosecutors ordered the detention of 46 people, including players, club presidents, commentators and a referee, over insider betting. A Turkish court later jailed 20 suspects, including Super Lig players, pending trial.