Twenty-two female escorts were arrested last week during a two-day sting in the Denver metro area.
The women were advertising on two websites — DenverBackPage.com and Preferred411.com, according to the FBI.
Investigators said the women used the websites to advertise for the purposes of prostitution and to verify “clients.”
All 22 escorts were arrested for prostitution-related offenses, the FBI reported.
The joint investigation involved Denver police, Aurora police, Lakewood police, the FBI, Organized Crime Coalition (C-TOCC), and the Innocence Lost Task Force.
Officials said they began the investigation into women advertising on DenverBackPage.com and Preferred411.com because of possible ties between those types of websites and human trafficking violations.