Police in India swooped down early Sunday morning on the hunger strike venue of the country's most popular yoga guru who was leading his followers in a mass fast, part of a populist campaign to fight corruption.

The New Delhi police used tear gas to disperse the thousands of supporters of Baba Ramdev who was briefly detained.

A police spokesman said permission had been given to Ramdev to hold a yoga function for 5,000 people, not the more than 40,000 people who turned up at the venue.

Ramdev, who hosts a daily yoga television show, had erected a huge tent for his hunger strike against corruption. He has said millions of people want to see India free of corruption, and have social justice.

Ramdev was demanding a return of so-called black money, cash stashed in foreign bank accounts and used to pay bribes. He was also calling for the execution of corrupt government officials.

Critics charge Ramdev has ties to right-wing Hindu groups, and they question his sincerity, arguing he lives lavishly with money from his multi-million dollar business ventures. But his call to end widespread corruption appears to be resonating in a country still reeling from a $39 billion telecom scandal and a scandal-plagued Commonwealth Games that have seen some ministers end up in jail.