A yoga guru who founded a rigorous routine of exercises practised in steamy rooms around the world is facing legal action by six women who accuse him of rape and other sex attacks.

The most recent case, filed on February 13 in Los Angeles Superior Court, said Bikram Choudhury raped a Canadian woman who paid 10,000 dollars (£6,500) from her college fund for a nine-week class so she could teach the 26-pose technique to others.

Jill Lawler said she went into the class elated to learn from the master, but things quickly soured as she was expected to massage him while watching Bollywood movies late into the night with hundreds of other students and was sexually assaulted on several occasions.

"Throughout the sexual abuse, defendant Bikram Choudhury offered multiple explanations and justifications for his behaviour," the lawsuit said. "He would say, 'I'm dying, I need to you to save me. If I don't have sex I will die. You are saving my life, you are helping me'."

Choudhury did not return an email seeking comment, but lawyers representing him and Bikram's Yoga College of India said he never assaulted any of the women and prosecutors declined to bring charges.

"Their claims are false, needlessly bring shame upon the yoga community, and dishonour the health and spiritual benefits that Bikram Yoga has brought to the lives of millions of practitioners throughout the world," their statement said.

The Los Angeles district attorney declined to bring charges in a case against Choudhury in 2013 for lack of evidence, spokesman Ricardo Santiago said.

Choudhury, 69, has throngs of devotees of what he has called McYoga for its consistency - 90-minute classes taught exactly the same way in rooms heated to 105 degrees.

He leads teaching seminars in nothing but a black Speedo while his followers sweat in skimpy, tight clothing. Courses are rigorous, the hours are long and sleep deprivation is almost guaranteed. Choudhury can be charismatic and cutting.

While people credit hot yoga with changing their lives and many remain loyal to Choudhury, there has been a noticeable change since the first sexual assault allegations were levelled in 2013, said Benjamin Lorr, who wrote Hell-Bent, a book on extreme yoga that features Choudhury prominently.

Women told Mr Lorr during his research about encounters with Choudhury like those recounted in the current lawsuits. But no woman would go on the record until Sarah Baughn, a yoga champion, sued Choudhury for sexual assault.

Ms Baughn, 29, said there was such a cult-like atmosphere among the Bikram community that she had endured Choudhury's sexual assaults as just something that went with the territory. Others told her to separate the man from the teacher.

She was able to do that for a long time, connected financially, emotionally and spiritually to a practice that had helped her overcome scoliosis and depression. She was afraid to leave because Choudhury boasted of how he had ruined people and got them banished from the yoga world, she said.

Ms Baughn's lawsuit will go to trial in August. She no longer practises yoga.