Murat Taşhan, a Corum judge who sent 517 people from 21 different occupations to prison over their alleged links to the Gülen movement, was detained as part of a separate investigation into the group last week.
Tashan was taken into custody along with his 5 colleagues in Samsun where they had come for a judicial panel discussion. While he and his two other colleagues were released on judicial control, the remaining three were put in pre-trial arrest.
Among the people Tashan have arrested as a judge so far are district governors, judges, prosecutors, police chiefs, doctors, veterinarians, engineers, prison guards, court clerks, teachers, imams, police officers, businessmen, housewives and military officers.
Turkey survived a military coup attempt on July 15 that killed over 240 people and wounded more than a thousand others.
The government pinned the blame on the Gülen movement while the group denied any involvement.