A search operation was underway to trace the missing workers, they added.
Involved in road construction works in Damin circle of the Kurung Kumey district, the workers, engaged by a contractor, were executing the road projects of Border Roads Organisation (BRO). The incident took place last week but came to light only on Tuesday after the recovery of the body of a worker by the local people.
A district official said that the 19 workers, mostly from Assam, went missing last week from the road construction site and the body of one of them was recovered from nearby Kumey river.
The area is extremely remote with mountainous terrains and dense jungles. Extensive search operations are going on, the official said, adding that police and administrative officials also left for the site where one body was found early this morning.
The BRO has been constructing several infrastructural projects along the China border in Arunachal Pradesh. Local villagers and police feared that all the workers might have drowned in the Kumey river.
Villagers reportedly informed the police that the workers left their work site after the contractor refused to grant leave for some days and then the tragedy happened.
The workers had taken the shortcut jungle route to return to their homes in Kokrajhar and Dhubri of Assam.
A case has been registered.