The authorities are confounded. More than 100 terribly decomposed bodies surfaced in the river Ganga in Uttar Pradesh’s Unnao district this week, prompting the local administration to launch an inquiry and the Central government to send an investigation team to the region.

Ruling out foul play, the district authorities said the bodies were perhaps immersed in Ganga as part of last rites. They conjectured that a drop in the water levels may have pushed the bodies to re-emerge.

In Hindu tradition, there are several conditions that disallow cremation of a body and require that it be immersed in a river instead. At Delhi’s largest cremation ground, Nigam Bodh Ghat, many of the about 500 bodies brought in every day are returned because they are considered “unfit” for cremation, said Himanshu Sharma, a priest there.

Snake bite: Some Hindu sects do not permit a person killed by a snake bite to be cremated. “Snakes are a manifestation of Shiva,” said Sharma. “When their bite kills someone, the person is not considered dead because he has achieved immortal life in another world.”

Sadhus: Hindu saints too are not cremated. “Sadhus are revered as next to the supreme being,” said Bhanu Shankar Sharma, another priest at Nigam Bodh Ghat. “We cannot cremate a manifestation of the higher being in fire. They either take samadhi or have to be immersed in Ganga.”

Infants: Young children and infants are required to be either immersed in a river or buried.

Skin diseases: Those with visible skin diseases or smallpox are regularly returned from the cremation grounds. “Chickenpox and smallpox means that devi maa is in possession of the body, so we cannot cremate the dead,” said Sharma.

In 1988, the Supreme Court declared that it was illegal to immerse corpses in the Ganga.

Boatmen of Ganga

Downstream from Unnao lies the temple town of Varanasi, where 60,000 daily people take a dip in Ganga and every day bodies are brought from distant places for immersion. Prime Minister Narendra Modi, who represents Varanasi in the Lok Sabha, had made cleaning Ganga one of his key electoral promises. After his government came to power, he sanctioned Rs 2,000 crore for Ganga Action Plan.

Ecologists warn that the Ganga basin is the most polluted in the world, with contamination levels 3,000 times higher than the extent prescribed as safe by the World Health Organization.

The contamination does not faze the people who are closest to the river and play a central role in immersion of bodies: the boatmen.

Raju Kohia, one such boatman in Varanasi, said bodies are wrapped in banana leaves and a large stone tied to them being lowered into the water. Only Harish Chandra Ghat in Varanasi performs this rite, he explained, and some 30-40 bodies are taken there every day.

“The ghat provides salvation to each soul who dies,” Kohia said. “Families bring their dead here if the bodies cannot be cremated to make sure their souls achieve moksha in Ganga.”

Sometimes, the reason is different. Kohia explained that many people come to Varanasi with the wish of cremating their dead but cannot afford the expense. “It costs over Rs 25,000 for an elaborate puja, so many who cannot afford this just immerse the body in the river.”