However, Russian authorities fear it could be the possible pipeline break after the river turned bright red.
Social media users began sharing photos of the unnaturally red Daldykan River on Tuesday.
A few users suggested iron ore in the ground had changed the river’s colour, but others said industrial waste was a more likely reason. The river runs near to the Nadezhda metallurgical factory run by Norilsk Nickel, the world’s leading producer of nickel and palladium.
Russia’s natural resources and environment ministry said in a statement on Wednesday that it was investigating complaints of unknown chemical pollution, possibly caused by a “break in a Norilsk Nickel slurry pipe”.