"The mutilated body of a woman was retrieved from the debris Thursday. The death toll now stands at 11," district Superintendent of Police Sanjeev Arora said.
Arora said two people, a man and a woman, are still feared trapped under the debris and efforts are on to locate them.
The help of sniffer dogs attached to the National Disaster Response Force (NDRF) is being taken, he said.
The accident occurred Aug 10 at the Basundhara mining area at Kulda in Sundergarh district, 450 km from Bhubaneswar, when a group of villagers were allegedly collecting coal shells from an overburden dump that collapsed on them.
Overburden is the name given to the material above the coal reserve, which is removed before mining and dumped elsewhere.
Since that waste contains also low grade coal shells, people often sneak into the prohibited mining zone area to collect these from the dumps.