Firat Epozdemir, board member of the Istanbul Bar Association, was arrested last year on suspicion of belonging to the outlawed Kurdish militant PKK -- listed as a terror group by Ankara and its Western allies.

Epozdemir was released after spending four months in jail but remained under judicial supervision.

"The investigation into Ferat Epozdemir has ended with his acquittal," said Ibrahim Kaboglu, head of the city's bar association after the hearing, according to the Anka news agency.

The move came almost three weeks after an Istanbul court dropped another case against Kaboglu and his executive board for allegedly spreading "terrorist propaganda" and "false information".

Epozdemir was detained on his return from a mission to Europe's top rights body, the Council of Europe in Strasbourg.

Prosecutors had accused him of holding responsibilities within a group they say is an extension of the PKK, as well as being part of a WhatsApp group created by that group.

Separately, another Istanbul court sentenced Ramazan Demir -- one of the lawyers representing jailed Kurdish leader Selahattin Demirtas -- to more than 11 years in prison for "membership in a terror organisation" and spreading "propaganda".

Demirtas -- a once prominent leader within Turkey's Kurdish movement -- was arrested in 2016 at the height of his political career and jailed on a string of "terror-related" charges.

"In reality, this trial is a case against Kurdish lawyers and the right to a legal defence," said Serhat Cakmak, co-chair of the Association of Lawyers for Freedom (OHD) to which Demir belongs.

The lawsuit against the Istanbul Bar Association was filed after it demanded an investigation into the deaths of two journalists from Turkey's Kurdish-majority southeast who were killed in northern Syria in late 2024.