The court ruled that only four suspects should remain in custody after a crackdown on people affiliated with the Gulenist movement.
The editor of the Zaman mass-circulation daily newspaper, Ekrem Dumanli, was among eight people released by the court.
Four people remained in custody, included the head of the Samanyolu Media group, Hidayet Karaca. The other three being detained are the former head of the anti-terror division of Istanbul police and two local police officials.
Initially, 28 people were arrested on Sunday, with a number of releases since then. Officials had originally said the arrests of police officers, journalists and broadcasters were on charges of forgery, the fabrication of evidence and forming a criminal network that would work against the state.
There was criticism of the initial arrests from the EU and US, with many of the detained being journalists.
Request for arrest
At roughly the same time the eight were released, Turkish prosecutors requested an Istanbul court issue an arrest warrant for the US-based Muslim cleric Fethullah Gulen, for "leading a terrorist organization."
Gulen, who leads a broad-based Muslim group known as "Hizmet," meaning "service," has lived in the US state of Pennsylvania since 1999. A one-time ally of President Recep Tayyip Erdogan, he is now the President's number one foe.
Erdogan accuses Gulen of running a "parallel state." It is alleged that his network infiltrated the police and judiciary, ordering corruption allegations that brought down four of Erdogan's ministers last year.
rc/es (AFP, AP, dpa, Reuters)