Iranian security forces arrested Kurdish environmental activist Navid Kohnehpoushi in Marivan, Kurdistan province, on 31 October.
The Ministry of Intelligence first took hostage Kohnehpoushi’s brother after they did not find the activist at home.
They told his family that they would keep their other son in custody until the activist turned himself in.
Kohnehpoushi presented himself to the office of the intelligence ministry a few hours after learning security forces had taken his brother hostage.
The intelligence ministry released his brother after they arrested the activist.
Kohnehpoushi is a member of the Chya the Green Organisation in Marivan.
He has been active in controlling fires and planting oaks in the area in recent years.
