An Istanbul court on Wednesday ordered the conditional release of Taner Kilic, the head of Amnesty International in Turkey, held on terror charges that his supporters have long dismissed as "baseless".

The decision was met with thunderous applause, while Kilik's friends wept and hugged other activists who attended the hearing.

Kilic, who had been arrested along with 10 other activists, was being tried on terror charges that Amnesty branded "baseless allegations".

"It is an enormous relief that Taner will soon be back with his wife and daughters, sleeping in his own bed for the first time in almost eight months," Gauri van Gulik, Amnesty's Europe director said.

Kilic was first detained in June 2017 on suspicion of being a member of the group led by US-based Muslim preacher Fethullah Gulen.

Ankara accuses Gulen of ordering the attempted overthrow of President Recep Tayyip Erdogan in July 2016 -- a charge that Gulen denies.

The other 10 activists, including a German and Swede, were released last year from pre-trial detention after holding a workshop on an island off Istanbul, but their trial continues.

They are accused of links to Gulen and other outlawed groups including the Kurdistan Workers' Party (PKK), which has waged a three-decade insurgency against Turkey, and the far-left Revolutionary People's Liberation Party-Front (DHKP-C).

- 'Good sign' for activists -

Kilic, who was held in Izmir in western Turkey, appeared in court via videolink and insisted he had proved his innocence through reports presented to the court.

Authorities accused Kilic of having an encrypted messaging application on his phone in August 2014 called ByLock, which Ankara claims was especially created for Gulen supporters.

Kilic has categorically denied having the app, while Amnesty says two independent forensic analyses that they commissioned found that there was no trace of ByLock ever having been on his phone.

Ozlem Dalkiran of Avaaz and Citizens' Assembly -- one of the activists also on trial -- said she was "very happy".

"It is a positive development and hope it will be good sign for other human rights cases," she told AFP after the verdict was delivered, adding: "The next step is acquittal."

Amnesty's Gulik said it would be a "brief moment to celebrate" but said "tomorrow we will continue our struggle to have all charges dropped against Taner, the Istanbul 10, and all other innocent victims wrongfully caught up in this vicious crackdown".

Erdogan has previously said that the activists were detained after they were working against the government, comparing them to those involved in the attempted coup.

The next hearing will be on June 21.