Several hundred people gathered for the third day in Armenia's capital, Yerevan, to demand a full investigation into the recent death of activist Artur Sargsian.
Sargsian, 49, passed away on March 16 just days after being released from prison following a 25-day hunger strike.
One of the doctors who treated the activist said he died of heart failure after being moved to a hospital for emergency surgery.
Investigators said they have opened a criminal case into his death.
The autopsy was planned for March 18, but it was reportedly postponed at the request of Sargsian’s family.
Sargsian was in prison on charges of aiding opposition gunmen last summer.
He had been accused of delivering food to armed members of a radical opposition group during their two-week standoff with security forces.