Villagers near the site of the Nam Khan 2 hydropower plant have reported hundreds of dead fish floating in the river by the dam.
The incident occurred in Phouxangkham Village, Xieng Ngern District, Luang Prabang Province on Monday.
An official from the Xieng Ngern Agriculture and Forestry Office in Luang Prabang Province told Laotian Times yesterday that the fish deaths are now under investigation.
Authorities of Xieng Ngern District have found that the water in the locality has a foul odor.
While many villagers are afraid, some have reportedly cooked the fish without any health problems reported.
Authorities have taken samples of water for testing at the Xieng Ngern Office of Natural Resources and Environment and are awaiting the result.
The Nam Khan 2 Hydropower Plant opened in December 2015. It is a reservoir-style project consisting of 2 turbine units with an installed capacity of 130 MW.
It is unknown if the operation of the hydropower plant is related to the fish deaths.