Police swooped early on Sunday on India's most famous yoga guru, detaining him briefly and using teargas to disperse his supporters and evict them from a huge tent in the capital where they were on a mass fast against corruption.

The saffron-robed Swami Ramdev, who rose from an illiterate family to host a television show with 30 million viewers and owns a 'peace' island in Scotland, began his fast on Saturday in a tent the size of four football pitches in the heart of the capital with tens of thousands of supporters.

'The permission was for a yoga camp for 5,000 not for 50,000 people for agitation. We have cancelled the permission and asked them to move out,' said Delhi police spokesman Rajan Bhagat.

The Congress-led coalition government, whose political authority has been battered by corruption scandals and high inflation, had been negotiating with Ramdev, whose demands included bringing back billions of dollars of illegal wealth stashed abroad and the death penalty for corrupt officials.

The government had said on Saturday it had agreed to most of Ramdev's demands but he appeared defiant late on Saturday, calling on his supporters to continue fasting.

The eviction could harden Ramdev's stance and spark protests by his millions of supporters across the country and could dent the government's popularity in the electorally important northern states of India.

Ramdev's fast came after a similar one by social activist Anna Hazare, whose April campaign rang a chord with millions of Indians and forced the government to make legislative concessions on an anti-corruption bill that effectively gives India an independent ombudsman to battle graft.

Both campaigns have underscored how India's traditional national parties are struggling to deal with the growing anger at middle class Indians increasingly fed up with graft, leaving a political vacuum that figures like Ramdev can fill.

Investors worry the trouble will force the government to pay less attention to reform bills, such as making it easier for industry to acquire land, postponed because opposition protests over graft led to deadlock in parliament.-Reuters