According to the Hurriyet newspaper, Birol Erdem was detained together with his wife Gulumser Erdem in Ankara early on Saturday as part of an investigation conducted by the Ankara Chief Public Prosecutor.
Erdem gave testimony as witness within the framework of the investigation over Gulen's followers, which was launched last year, the newspaper reported.
A military coup attempt took place in Turkey in July 2016 but was quickly suppressed by government forces. More than 240 people were killed and an estimated 2,000 were wounded during the incident. Turkish authorities accused Gulen, who has lived in the US state of Pennsylvania since 1999, and his followers of playing a key role in the coup. Gulen has denied the accusations and condemned the attempted coup.
Since July, Turkey has arrested thousands of military personnel, activists and journalists on suspicion of links with Gulen.
Turkish Prime Minister's Chief Adviser detained over suspected links to Gulen
04 June 2017
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Turkish Prime Minister Binali Yildirim's chief adviser was detained on Saturday on suspicion of having links to Islamic cleric Fethullah Gulen, accused by Ankara of masterminding last year's failed coup, local media reported Saturday.
