Scores of bodies have been recovered in the river Ganges in the northern Indian state of Uttar Pradesh, prompting the authorities to order a probe.
Reports said the bodies were of people who were dumped in the river or buried on the banks after their families could not afford a proper cremation.
The Ganges is India’s most sacred river.
But the 2,500km (1,500-mile) river has been badly polluted by industrial waste, farm pesticides and sewage.
Prime Minister Narendra Modi vowed to clean up the river after his landslide election victory last year.
Reports said that authorities in Uttar Pradesh’s Unnao district were taken by surprise when scores of bodies were found floating near the banks of the river on Tuesday.
Senior local official Saumya Agarwal said that “some 35 to 50 bodies” had been recovered and arrangements were being made to dispose of them.
“I don’t think we can cremate the bodies as their condition is very bad,” she said.
She said the water levels in the river had receded in the region “and hence the bodies became visible”.
A multi-billion dollar initiative to clean up the polluted river has largely failed, environmentalists say.
They say the river supports more than 400 million people, and if the unabated pollution is not controlled, it will be the end of communities living along the banks.