A four-month police investigation has led to the arrest of a Livonia woman who is accused of human trafficking at several massage businesses in Oakland and Wayne counties where the victims were living, officials said.

Zixuan Wan, 44, is charged with three crimes so far — human trafficking-enterprise resulting in commercial sexual activity, human trafficking enterprise, and keeping a house of prostitution. More charges are expected soon as the investigation, described as “large-scale,” continues, officials said.

Wan is out of custody after 47th District Magistrate Michael Sawicky arraigned and then released her on a personal bond — requiring no cash or surety to be posted. Conditions of bond include GPS monitoring and surrender of her passport.

The ongoing investigation into Wan and her alleged crimes is led by the Farmington Hills Police Department in collaboration with the Oakland County Sheriff’s Office and the Westland Police Department. It was launched last November, the Farmington Hills Police Department’s directed patrol unit became aware of an unlicensed massage business in the city where illicit services were offered, according to Farmington Hills police.

Earlier this month, police executed multiple search warrants at Wan’s massage businesses in Farmington Hills, Commerce Township and Westland, her home in Livonia, and banks where she allegedly deposited proceeds from the illegal acts, Farmington Hills police said.

On March 5, law enforcement found several human trafficking victims living in Wan’s businesses, police said, and subsequently brought them to CARE House of Oakland County and Common Ground for services.

The searches have turned up approximately $140,000 in cash and several firearms so far, police said.

“The successful outcome of this investigation is the result of the strong partnerships that the Farmington Hills Police Department maintains with agencies throughout Oakland County and beyond,” Farmington Hills Police Chief John Piggott stated in a news release. “I’m continually impressed with the men and women of the Farmington Hills Police Department who are constantly seeking out training opportunities and bringing the skills learned back to the department. These skills directly lead to law enforcement intervention rescuing these vulnerable women from further exploitation. Because of their excellent work and our collaboration with outside agencies, a dangerous human trafficker will be held accountable.”

Wan’s next court appearance is scheduled for March 21 before 47th District Judge Marla Parker.