Pinch, a former MLA, was on a rafting expedition, Papum Pare Superintendent of Police (SP), Tumme Amo said.
An eight-member team had gone for rafting on Friday and stayed on the river bank near the confluence of Popum and Poma rivers.
However, Pinch was found missing early in the morning and on search his body was found floating at Hatimatha in between Basar Nallo and Rana Ghat on Assam side, the SP said.
A police team rushed to the spot, fished out the body and brought it to Doimukh and handed over to the family members for conducting the last rites, Amo added.
He won from the Doimukh assembly constituency in 2004 as an Independent candidate.
Disclaimer: No Business Standard Journalist was involved in creation of this content