Four Chinese nationals have been arrested on suspicion of recruiting women from China to work in brothels set up in residences in Monterey Park and San Gabriel.

According to Immigration and Customs Enforcement officials, the weekend bust resulted from a nine-month investigation into a far-reaching prostitution enterprise that relied on word of mouth and personal referrals to lure customers into private condominiums for commercial sex.

Court papers allege that the defendants engaged in various types of immigration fraud, including using fake documents and false marriages to recruit Chinese women, many with valid student visas, into a life of prostitution in the San Gabriel Valley.

"We found no evidence of force or coercion. These women were willing participants," said Claude Arnold, special agent in charge of ICE's office of Homeland Security Investigations in Los Angeles. "But regardless of whether these women were actively trafficked, they are still being exploited and these operations degrade the quality of life in our neighborhoods."