Turkish authorities detained a prominent journalist late Thursday less than 24 hours after he was released in connection with the probe into the attempted putsch in July, local media reported.

Journalist and writer Ahmet Altan was initially freed before dawn on Thursday while the Istanbul court placed under arrest his academic brother Professor Mehmet Altan.

But the journalist was detained again after an arrest warrant was issued late Thursday, the Dogan news agency reported.

Hours earlier, the court placed Mehmet Altan under arrest on charges of "attempting to remove the government or attempting to obstruct its work", the official news agency Anadolu reported.

He was also charged with "being a member of a terrorist organisation", referring to the movement of Muslim cleric Fethullah Gulen.

The Altan brothers were first detained on September 10 and were two of the most high-profile figures detained in the controversial crackdown after the botched coup on July 15.

Their case sparked an international campaign for their release with famous writers criticising the Turkish government.

Gulen's group is accused of launching the failed coup. Gulen denies the accusations and ridicules Ankara's designation of his group as a terror outfit.

Ahmet Altan now faces the same accusations in the warrant issued prior to his detention, Dogan reported.

He has written for some of Turkey's best dailies including Hurriyet and Milliyet, as well as founding the opposition daily Taraf. His brother has written several books on Turkish politics.

His brief freedom came after almost 12 hours in court in a marathon overnight hearing.

The pair were detained over comments in a talk show on the Can Erzincan TV channel on July 14, the eve of the coup which according to state media contained "subliminal" messages that the putsch was imminent.

The broadcaster, seen by the authorities as pro-Gulen, has since been shut down.

The Altan brothers' detention was swiftly condemned by rights groups and fellow writers as alarm grows over what activists claim is Turkey's repeated attacks on freedom of speech.

Nobel-winning Turkish novelist Orhan Pamuk had lashed out at the authorities after the original detention of Ahmet Altan, criticising the crackdown as driven by "the most ferocious hatred".

Pamuk was among nearly 300 famous writers and others, including Salman Rushdie and J.M. Coetzee, who signed an open letter urging the authorities to release the journalist and to respect freedom of expression.

Dozens of journalists have been detained while more than 100 media organs have been closed down since the putsch attempt.

The Turkish government insists those detained were not engaged in normal journalistic activity.