Vahyettin Yahya Bayat, a 65-year-old Turkish businessman under arrest as part of an investigation into the Gulen group, passed away after a heart attack on Friday morning, the TR724 news portal reported.
Bayat lost his life in his cell in Diyarbakır Prison following a heart attack. It was reported that Bayat has been suffering severe heart problems.
Bayat was among some 60,000 people who were arrested over links to the Gülen group, which the government accuses of masterminding the July 15 failed coup attempt.
The group denies any involvement.