BUENOS AIRES, Argentina (AP) — Argentine investigators say they believe they have discovered the body of a protester whose disappearance prompted large protests.

Officials say Coast guard divers found the body in a river in southern Argentina and an investigator involved says there are elements to believe it's Santiago Maldonado. He spoke on condition of anonymity Wednesday for lack of authorization to speak publicly.

It was found near the location of the Aug. 1 demonstration by Mapuche Indians who were blocking roads to demand lands. People there say they saw police beat and detain Maldonado. Police never confirmed the arrest.

His disappearance prompted tens of thousands to protest in Argentina and led to expressions of concern by international rights groups. U2 lead singer Bono raised the issue with President Mauricio Macri last week.