Image caption Should the religious festival be a money-spinner?

Indian religious leaders have reacted angrily to a proposal to sell broadcast and advertising rights to the world's biggest religious festival.

Commercialising next year's Kumbh Mela would be highly offensive, they say.

The ancient Hindu gathering takes place in the northern state of Uttar Pradesh, attracting tens of millions of people.

The BBC has learned that the state government wants to offset the cost of the event by selling media access - critics say they have no right to.

In May Uttar Pradesh chief secretary Jawed Usmani sent a letter instructing the local administration to "generate revenue by auctioning advertising and telecast rights" to the event, BBC Hindi's Ram Dutt Tripathi reports.

'Impossible'

The Kumbh Mela has been held on the banks of the Ganges for thousands of years. It is at its largest once every 12 years when it attracts tens of millions of people.

In 2001, more than 40 million people gathered on the main bathing day at Allahabad, breaking a world record for the biggest human gathering.

At the 2013 event, the numbers are expected to be even higher.

In this mela different cultures come together - and how can one organisation monopolise it? Prof Dhananjay Chopra, Allahabad university

Although it is a religious festival, the state supports it by providing amenities, from security to sanitation.

Religious leaders have always opposed attempts by the state or big business to cash in on the event.

They say the festival does not belong to the government and they have no right to sell access to it.

So the government plan leaked to the BBC to raise money by auctioning exclusive broadcast rights is already proving controversial.

Senior state government officials, too, have written to the Uttar Pradesh administration, expressing their reservations over the proposals.

Some police officials are also believed to view the plan as unworkable. They fear that if it causes religious offence that could become a law and order problem.

It is also unclear how a deal would be implemented on the ground.

When many millions of people gather in the open air, it will be impossible, critics argue, to stop unauthorised people from filming the main events.

Analysts say the government plan is likely to cause widespread offence and could spark a legal battle about religious freedoms.

"This is not an ordinary mela but a gathering where social concerns are very important," Allahabad university professor Dhananjay Chopra, who has written a book on the Kumbh Mela, told the BBC.

"In this mela different cultures come together - and how can one organisation monopolise it?

"These days, when every citizen has tools to broadcast themselves, the plan is impossible to implement."