A 35-year-old gas station employee from Ioannina, northwestern Greece, is believed to have led the far-right group Combat 18 Hellas, according to police who arrested 11 suspected members of the organization earlier this week.
Of the 11, seven are to face an investigating magistrate on Saturday on charges of running a criminal organization.
The other four are to face the same magistrate on Friday on a series of charges ranging from arson to illegal weapons possession.
The group is believed to be behind more than 30 attacks, chiefly on anarchist squats and Jewish memorials.
The 35-year-old suspected leader is belived to have coordinated those attacks via a fake profile on Facebook, using the name Alexandros Tsambanikas.