Buenos Aires: An Argentina-based yoga group sexually exploited vulnerable women it called “geishas” to get money and influence from wealthy and powerful men around the world, including opera star Placido Domingo, who knew the organisation’s leaders for more than two decades, according to interviews with former members and local authorities.

A sprawling investigation into the sect-like Buenos Aires Yoga School, which operated for over 30 years in Argentina’s capital, has uncovered what authorities are calling a criminal organisation involved in sex trafficking, money laundering, involuntary servitude, illegal practice of medicine and other crimes. Nineteen members have been arrested in the investigation that reaches into the US, where six more suspects are sought.

Despite its name, the school did not offer yoga classes. Leaders are accused of preying on people to join their ranks with promises of eternal happiness and then exploiting them sexually and financially, according to charging documents.

Former members of the school and officials investigating the case said that the group forced female members to work as “geishas” who were assigned to make guests feel welcome at the school, with sex part of the expectations. Influential or wealthy men were matched up with members of the “Geishado VIP,” one of many groups of women that were forced to have sexual encounters in exchange for money and influence that benefited sect leaders, according to the charging documents. Some women were sent to the United States and Uruguay to have sex with men, a practice that amounted to slavery, authorities said.

Some members of the group were reduced to “a situation of slavery,” forced to have sexual encounters and tasked with menial chores at the school like cleaning and cooking, according to the investigative documents and a police official.

Domingo found himself embroiled in the scandal after law enforcement officers carried out dozens of raids in Buenos Aires in August targeting the school. The famed tenor was “a consumer of prostitution” but isn’t accused of a crime because prostitution is legal in Argentina, said a law enforcement source in Argentina who, like other police and judicial sources in Buenos Aires, spoke on condition of anonymity because the investigation is ongoing.

Authorities released wiretapped phone conversations from earlier this year in which a man they identified as Domingo appears to be arranging a sexual meetup at his hotel in April in Buenos Aires with Susana Mendelievich, a concert pianist who prosecutors say was a sect leader in charge of the “Geishado VIP.”

In one of the wiretaps, Mendelievich talks with another sect leader about how the group had tried unsuccessfully for years to use its music connections to recruit Domingo into the group but it was worth trying again while he was in Buenos Aires in April for a series of concerts. In another wiretap, Mendelievich asks sect leader Juan Percowicz if she can take Domingo to “the museum,” the moniker used to refer to the top floor of their 10-story building where influential men had sex with group members. Mendelievich, 75, and Percowicz, 84, were detained in the raids in August; both were released this week to house arrest.