MUMBAI, India — Aamir Khan spent more than two decades as one of India’s most admired movie stars, appearing in a string of socially conscious but mainstream films. Now he has gained even more fame as the host of a hugely popular weekly television show that is calling attention to some the country’s longstanding social problems.


Taped in front of a live audience, Mr. Khan’s show, “Satyamev Jayate,” or “Truth Prevails,” is something more than a talk show but less than “60 Minutes.” Mixing Oprah-style interviews on a couch with short reports from the field, it tries to shine a spotlight on festering issues like dowries, domestic violence and indignities in the caste system.


In just three months the show has become a national phenomenon, distributed in seven languages and drawing a cumulative audience of nearly 500 million, according to Star India, India’s largest private TV network, which is owned by News Corporation and which commissioned and broadcast the show.


One of the early programs, in May, provided a vivid example of the show’s influence. Mr. Khan, 47, highlighted a seven-year-old sting operation by two TV reporters who had broadcast footage of more than 100 doctors offering to illegally abort female fetuses. While the legal cases against them languished in India’s notoriously slow courts, the doctors continued to practice medicine.


But just days after Mr. Khan featured the topic on his show, the top elected leader from the State of Rajasthan, where the journalists did their investigation, met with Mr. Khan and promised to have the cases transferred to special courts that expedite the dispensing of justice.


That kind of swift reaction has made Mr. Khan — variously described as India’s Oprah Winfrey, George Clooney or Bono — increasingly sought after by policy makers, social advocates and others who see him as a savior or champion for their causes. In addition to meeting with the chief minister of Rajasthan, he testified before a committee of Parliament about the country’s health care system after he did a program on medical malpractice. And last week he met with Prime Minister Manmohan Singh to press for a government ban on the practice of having human waste cleaned and carried away by people born into the lowest rungs of the Indian caste system.


He also has a weekly column in The Hindustan Times, takes calls from viewers on a weekly national radio show and is frequently interviewed on prime-time TV news shows.


“Mr. Khan is doing the nation a service by raising important issues which need greater public debate,” said Dr. K. Srinath Reddy, president of the Public Health Foundation of India, which is financed by the government and nonprofit organizations like the Bill and Melinda Gates Foundation.


Shyam Benegal, a respected TV and film director and a former member of the upper house of Parliament, said Mr. Khan has done what many others have failed to do — reach the Indian mainstream by using Bollywood tropes in the service of larger causes. His shows, for instance, always include musical performances, frequently show him crying as he interviews his guests and include jokey banter.


“This is effective because Aamir Khan is a film star,” said Mr. Benegal, who once made shows for the state-owned broadcaster, Doordarshan. “And he is a pretty good P.R. man for himself, as well. And all those things help.”


Mr. Khan’s fame has helped the show attract sponsors like India’s largest cellphone carrier, Airtel and the foundation arm of one of the country’s largest companies, Reliance Industries.


In an interview earlier this month — after spending two hours at the gym to prepare for an coming action film — Mr. Khan likened his approach to the show to his 2007 movie, “Taare Zameen Par” or, literally, “Stars on Earth.” The film, which he directed and starred in, told the story of a family’s and school’s inability to meet the needs of a dyslexic child.