Sam Banks, 20, collapsed with severe sickness and diarrhoea. By the time he was taken to a hospital in New Delhi, he was dead.
"I understand from friends out there that he (Sam) had been swimming in the Ganges," The Sun on Thursday quoted Sam's father Graham as saying.
"He was a fantastic young man, with hundreds of friends, and was so excited about India. He'd been saving up for a year - it was the first time he had been out of Europe."
A postmortem examination in India failed to detect the cause of his death. His body has been flown to Steep, Hants, for a second autopsy.
The river Ganges, considered holy, is one of the dirtiest rivers in India, with untreated sewage and industrial chemicals being dumped into it. The government and various agencies are involved in efforts to clean it up.
Sam's mother Louise said: "We're devastated. He had such a bright future."
A day before he died Sam learnt he had been accepted to study film at the London College of Communication.
London: A British gap-year student died in India, days after swimming in the river Ganges.
First Published: Thursday, July 01, 2010, 17:47