Bikram Choudhury likes to get people hot and bothered and he likes to get them in a twist.
The yoga guru, who lists Madonna, Raquel Welch and Serena Williams among his celebrity followers, is also hugely protective of his famous and controversial style. Anyone thinking of adding, altering or in any way changing his 26 copyrighted and trademarked postures - each to be performed twice in a heated room - has received a "cease and desist" letter from his lawyers.
The letter is curt and pointed: if a yoga teacher has not attended a $5,000-per-person training programme and is not paying a studio franchise fee, he or she should not be teaching "Bikram" yoga. The letter threatens penalties of $150,000 for any infringement.
But now the yoga teachers are hitting back and a federal lawsuit has been filed against Mr Choudhury claiming yoga is a 5,000-year-old tradition that cannot be owned. And if Mr Choudhury doesn't like it? Well, say the enthusiasts, he's flexible enough to know where to shove it.
Elizabeth Rader, a copyright lawyer and a fellow at Stanford University, is representing the group Open Source Yoga Unity. She said: "We're not disputing that Mr Choudhury did something creative and useful in putting the postures together in a certain order. Our belief is that you can't treat the poses as private property. Right now, people are trying to teach yoga but are not sure what is going to get them sued."
The growth of Mr Choudhury's form of yoga has been phenomenal. Since he arrived in the US from India in 1971 his yoga has developed a cult-like following. He claims that he is opening two new studios every day and that worldwide he has more than 800 schools in 220 countries, including Britain. He is estimated to be worth $7m. His yoga's success has been aided by its popularity among celebrities such as Raquel Welch, who ironically also fell foul of Mr Choudhury's lawyers when she published a book on yoga.
Mr Choudhury, 57, is quite blunt about his decision to go after those teachers he believes are infringing his copyright. He told Business 2.0 magazine: "I have balls like atom bombs, two of them, 100 megatons each. Nobody fucks with me."
The guru claims that his yoga - ideally performed in mirrored rooms at a temperature of 105F (40C) - can cure everything from heart disease to hepatitis C. And he claims that he has no alternative but to protect his livelihood. "I'm not happy about it," he recently told reporters. "When I first came here I never charged a dime. But my students said, 'You have to charge something or else nobody will believe you know something.'"
There are plenty who think Mr Choudhury is not only going too far but also has lost sight of what yoga is supposed to be about. Mark and Kim Morrison, who opened a small yoga studio in northern California and invested more than $100,000 in the project, were last year sued by Mr Choudhury's lawyers. Although they had planned to fight the action, their insurance company opted to settle out of court for an undisclosed sum. Mr Morrison said yesterday: "In his book he talks about how his guru told him to go to America and teach yoga. That is what we are doing and he is trying to stop us."
The Morrisons no longer advertise themselves as practitioners of Bikram yoga, which they say was restricted to a list of postures including the half moon pose (figure 2), the eagle (4), the triangle (9), the tree (11), the cobra (16), the half tortoise (21) and the rabbit (23).
Mr Morrison said: "We would have students saying, 'Do you have anything other than these 26 postures', and we'd tell them that actually, yes, there was a lot more."
Others support the guru. Lynn Whitlow, who teaches Bikram yoga in San Francisco, told the San Francisco Chronicle: "His desire is not to police yoga but to maintain the purity of his teaching. People who are suing him over this take his class to teach his yoga, and then decide they want to change the yoga. If you want to change it, do it, but don't call it Bikram yoga. It's like Starbucks. You go in knowing what you want."
No one from Mr Choudhury's headquarters in Los Angeles was available for comment yesterday.