The McLennan County Sheriff's Department arrested a woman in connection with a massage parlor sex trafficking operation.

The woman, Lirong Tong, was arrested last week at a massage parlor in San Marcos and is facing a charge of engaging in organized criminal activity, KCEN-TV reported.

Tong is currently being held in Hays County jail.

Parnell McNamara, the sheriff for McLennan County, said his office had been investigating massage parlors for several months in multiple Texas cities and tracked Tong by following the money that went through the parlors, the news agency reported.

McNamara told the news agency that the public needs to be watching for new massage parlors in the community and noted several signs to tell when a massage parlor was a sex trafficking ring, including parlors that are seemingly open at odd hours, have mostly male clients and the female workers never leave the buildings.