'The Polar Division of Norilsk Nickel does not confirm a leak of emergency discharge of industrial waste into the Daldykan River which could have affected its state.' Picture: Vkontakte

The disturbing images are from an river close to Norilsk, in Kransnoyarsk region. Locals say it is far from the first time the waters have turned bright red. The river is said to be polluted by a discharge from Nadezhdinsky factory, also known as Nadezhda Metallurgical Plant, which processes nickel concentrate.

It is owned by giant Norilsk Nickel, but the company has questioned claims about a discharge, but said checks are underway.

The river is said to be polluted by a discharge from Nadezhdinsky factory. Pictures: Vkontakte

A spokesman said that 'as of today, the Polar Division of Norilsk Nickel does not confirm a leak of emergency discharge of industrial waste into the Daldykan River which could have affected its state.

'However, environmental monitoring around the river and adjoined production facilities of the company is being held, including helicopter flights.'

'As far as we know, the colour of the river is today no different from normal.' Picture: Zolotarev Rostislav

As a precaution, production at the facility was reduced. The company provided a picture of the river to a local news agency, Tayga Info, which showed the waters with a normal colour.

However, it was not clear if the picture showed the same stretch of river. 'As far as we know, the colour of the river is today no different from normal,' said a company source.