All the deceased were working at a road construction site at Umphung village, which is about 15 km away from Saipung in the district, they said.
"We were informed of the incident yesterday and at present the post mortem is being conducted at Khliehriat, the district headquarters," East Jaintia Hills Superintendent of Police (SP) M K Dhkar said.
The post-mortem is being conducted to find out the exact cause of death. All the deceased have been identified and are from Dhubri district, he said.
The same was grounded together and consumed before they all went to sleep on Sunday night. All the workers were found dead on Monday morning and the suspicion was that they had consumed poisonous fruits, police said.