Police arrested Zurab Japaridze, one of the leaders of the Coalition for Change, on the morning of December 2.
A video was released showing Japaridze being dragged in a police car.
His whereabouts are currently unknown. The party leaders are trying to determine where he was taken by the police.
The detention was preceded by a confrontation between police forces and protesters.
Protesters blocked the road with bunkers to protect themselves from the brutality of the special forces, which was met with violence from the police. They detained several more protesters by using excessive force.
