Salman Khan has acted as an AIDS victim in Bollywood's first ever feature film on the issue - for free.

"He did not charge me a penny," said award-winning actress-turned-director Revathy Menon who has directed "Phir Milenge", India's first film tackling HIV/AIDS - a disease that for most Indians is a stigma.

"We wouldn't have been able to afford him - he is a big, very big star," Menon told.

"I told him this was our budget, he just smiled and asked me to give whatever I could. And then, gave all the money away to charity.

"So whatever money we could give him has gone to a school he runs for children in (the) Bandra (area of Mumbai). He has an idea that all of us should take care of our own areas - and the world will become better. I think it's very correct."

The film, to be released worldwide Aug 27, also stars Shilpa Shetty and Abhishek Bachchan.

Menon said she didn't think of casting Khan. "He was just too big for our budget. Shilpa was in the project and she was also acting in 'Garv' opposite Salman.

"She told him about the project and he got interested. Then one day, I was talking to him and I told him that I was having trouble finding the right actor. He said, 'Well, you haven't asked me yet.' And it happened."

The film is being supported by UNAIDS.

Menon, who regularly campaigns for disability rights, also crusades against the AIDS stigma. "I have known HIV-positive people who have led a healthy life for 17 years after detection. It all depends on how well you take care of yourself and how much support you get from family and friends.

"My main desire is to remove this stigma."

There are currently an estimated 43 million people with HIV/AIDS in the world, with five million new cases being added every year. India, with 5.1 million HIV/AIDS cases, has the second highest incidence of the disease in the world after South Africa.

Menon has acted in more than 95 films in five Indian languages. "Mitr - My Friend", her first directorial venture, won the National Award for Best English Feature Film. Menon also received the Silver Peacock Jury Award for Direction at the International Film Festival of India in 2002.