Turkish police have detained the main opposition party leader's lawyer as part of a probe into the group led by the US-based Islamic preacher blamed for last year's failed coup.
Celal Celik, a lawyer for Republican People's Party (CHP) leader Kemal Kilicdaroglu, was taken into custody in Ankara after a police raid at his home, state-run news agency Anadolu said.
According to his biography on the CHP website, Mr Celik is a former judge who now also works as a member of the party's high disciplinary committee.
He is accused of being close to a former science, technology and communications adviser to Mr Kilicdaroglu, Fatih Gursul, who was detained in December over alleged links to the cleric Fethullah Gulen, Anadolu reported.
Turkey accuses Mr Gulen, who lives in self-imposed exile in Pennsylvania, of ordering the attempted putsch, allegations which he denies.
The detention comes after allegations Mr Celik cancelled his subscription with satellite TV provider Digiturk after it removed Gulen-linked television channels Bugun and Samanyolu, Anadolu and private news agency Dogan said.
There were suspicions he cancelled it because of "instructions from Gulen", Dogan reported.
Mr Celik will be taken to Istanbul, Anadolu said, as the investigation is being conducted by the Istanbul chief public prosecutor.
More than 50,000 people have been arrested since the July 2016 coup attempt over suspected connections with Mr Gulen while nearly three times that have been suspended or fired from the public sector.
Mr Kilicdaroglu has been fiercely critical of the government and the subsequent crackdown, accusing president Recep Tayyip Erdogan of a "civilian coup".
Critics including Mr Kilicdaroglu say the purge has gone well beyond the coup plotters and targeted all kinds of dissidents but the government argues it is necessary to remove real threats to the state.
The Ankara chief prosecutor issued another 71 arrest warrants for people accused of links to Mr Gulen, including eight individuals who work in the education ministry, Anadolu said. At least 27 had already been detained, it added.