With her dimpled smile and wholesome good looks, Preity Zinta has danced and lip-synced her way into the top ranks of Bollywood stardom. But nothing prepared the 28-year-old daughter of an Indian army officer for the critical acclaim that greeted her latest performance, on the witness stand in a Bombay courtroom.

"Bravo Preity," exclaimed the headline on an editorial in the Indian Express. "Bollywood's Only Real Hero," agreed the Hindustan Times.

The outpouring of praise was prompted by Zinta's willingness to do what no other Bollywood star has until now had the nerve to do: offer evidence about the pervasive influence of organized crime in the increasingly profitable and global Indian film industry.

In a closed court session this month, the details of which were promptly leaked to the press, Preity testified that she had been the target of an extortion threat two years ago by a man claiming to represent Chota Shakeel, a Pakistan-based gangster. Her testimony came in the high-profile trial of Bharat Shah, a leading Bombay diamond merchant and film financier, on charges involving links to the underworld.

Before Zinta's appearance, the prosecution had called a dozen other film personalities to testify, but all had turned uncooperative on the stand, recanting earlier statements or suddenly going fuzzy on key details -- evidence, police say, of the underworld's power to intimidate even the most macho and highly paid stars.

So what prompted India's "Preity Hero," as one headline writer dubbed her, to break the code of silence on the nexus between Bollywood and the mob?

In her first interview since testifying, Zinta owned up to a mixture of motives, from an altruistic desire to "do the right thing" to more pragmatic considerations, such as wanting to "get out of the court" quickly and fearing the legal consequences of contradicting her taped statement to police.

Asked whether she felt her testimony had put her safety at risk, she replied, "for sure," lashing out angrily at law enforcement officials who she believes leaked the details of the supposedly secret court proceeding.

"It was a huge risk I was taking in there, and I expected to be protected," she said, sitting in her office in a Bombay suburb near several of the major studios. "I felt extremely betrayed."

Zinta said she had no wish to launch a personal crusade against underworld influence in Bollywood -- "I wouldn't want it to be made into a big deal, because it's just going to create lots of problems for me in the future" -- and defended fellow stars who have been accused of cultivating chummy relationships with mob bosses based in Karachi, Pakistan, and Dubai, in the United Arab Emirates.

"If you meet someone and he comes and says hello, you can't just tell him to take a walk -- you say hello back," she said in her precise, convent-school English. "You think, maybe if I say hello I can leave. Do you know what I'm trying to say? It's a Catch-22 situation. It's not as black and white as we put it. It's not just, 'If you keep away from them you're good, and if you mix with them you're bad.' "

Zinta's ambivalence, to say nothing of her fears, reflects what police officials contend is a high degree of collusion -- some of it voluntary -- between mob figures and some of the biggest names in Bollywood.

As in the Hollywood of an earlier time, crime bosses have long cultivated social ties to the Indian film industry, basking in the reflected glory of its glamorous stars. In the mid-1990s, however, crime syndicates began looking for new sources of revenue following the collapse of the Bombay real estate market, which had provided them with money through extortion and other means, according to police officials here.

Bollywood was an obvious target. Churning out roughly 900 feature films a year, the industry's three-hour song-and-dance epics command huge audiences both in India and around the world, especially since the advent of new technologies such as satellite television and DVDs. At the same time, Indian filmmakers have had difficulty financing their projects by conventional means because India's government-owned banks had refused to lend them money until 2000, when the government changed its policy.

Crime syndicates were only too happy to step into the breach, offering loans to producers at rates of up to 36 percent, police say. "Anyone who has money could enter into Bollywood and start a movie," said D. Sivanandhan, an Indian Eliot Ness who investigated organized crime in the movie industry as a joint police commissioner, a job he has since left. "There were no qualifications, no entry fees. It was a wide-open field."

One of the most important mob financiers is alleged to be Shakeel, whose name turns up repeatedly in the Shah case and who is thought to be living in Karachi. Based on transcripts of telephone conversations that were secretly recorded by police and leaked to the Indian press last summer, Shakeel appears to be on good terms with a number of India's top producers, directors and stars, with whom he discusses financing arrangements and sometimes even creative issues.

"Be careful during mixing when you cut scenes," he tells one prominent director, who replies, "Yes sir. Yes sir."

Shakeel also chats amiably with Sanjay Dutt, a top Bollywood star who is facing criminal charges for alleged links to Pakistan-based gangsters blamed for a series of bomb blasts that killed 257 people here in 1993. When Dutt complains about another actor's habit of showing up late on the set, according to the transcript, Shakeel laughs and tells him not to worry: "He will be punctual in our project."

Crime bosses have also regarded Bollywood personalities as ripe targets for extortion, and those who don't cooperate can play a heavy price. A top music executive was killed by mob hit men in 1997. And in 2000, armed assailants shot and wounded Rakesh Roshan, a director and the father of heartthrob actor Hrithik Roshan. The director was allegedly targeted for refusing a gangster's demand to line up Hrithik's services for a movie he was backing.

Such episodes have contributed to an atmosphere of fear among Bollywood's glitterati, some of whom are under full-time police protection. (Zinta said she was offered protection after her testimony but declined for the sake of her privacy.)

For law enforcement officials, nothing so captures the corrosive influence of organized crime in Bollywood as the case against Shah, the diamond merchant-turned-movie mogul who owns a fleet of BMWs and reportedly paid 300,000 rupees, about $6,250, for an autographed pillowcase used by Michael Jackson during a stay at Bombay's Oberoi Hotel. The court case turns on allegations that Shah helped an associate of Shakeel's -- another Karachi-based crime boss named Dawood Ibrahim -- in an extortion scheme. Shah, who is currently free on bail, has denied any wrongdoing.

The case has also brought to light allegations of mob involvement in the making of "Chori Chori, Chupke Chupke," in which Zinta played a leading role. During the shooting of the film, Zinta received a phone call from a man who claimed to be an associate of Shakeel's, ordering her to pay 5 million rupees, about $104,000, or "face consequences," according to details of her testimony that were leaked.

Zinta declined to discuss the specifics of her testimony but confirmed the essential thrust of the reports. In the transcript of his phone conversation with Dutt, Shakeel denies threatening Zinta, telling the actor, "I will never demand money from the female species."

Zinta is in some respects an unlikely star. The daughter of an Indian army colonel who has since died, she was raised on military bases and attended a convent boarding school. She holds an English degree from Delhi University and pursued advanced studies in criminal psychology. One brother is a major in an armored unit currently stationed near the hostile frontier dividing Indian and Pakistani forces in Kashmir; another brother sells cars in Petaluma, Calif.

In person, Zinta projects a high degree of confidence, greeting a visitor with a direct gaze and a hearty handshake. Demurely pretty in a pink sweater and flowered skirt, she said she stumbled into acting largely by accident, though she seems to have adapted comfortably to the role. She lives in a luxury high-rise, tools around town in a black Lexus sport-utility vehicle and vacations in places such as Cannes and Sydney. The details of her romantic life, including a recent breakup with a top model, are breathlessly chronicled in the Indian press; she is currently dating a Danish engineer named Lars.

While Zinta's testimony is at best peripheral to the Shah case, police say she deserves credit for helping to shine a light on the extent of mob influence in Bollywood -- an important step in cleaning up the industry.

Perhaps because the job has yet to be completed, Zinta isn't exactly welcoming the attention. "I had a lot of people telling me I was very stupid," she said. "One thing everyone told me is, 'Preity, one person can't change the system.' "

The most telling reaction may have come at a television awards ceremony a few days after her court appearance. "I met this guy who walked up to me and said, 'Congratulations, you're the only crazy person in this industry.' "

Actress Preity Zinta has been the only major figure to testify on the power of organized crime in India's film industry.