REDWOOD CITY -- A South San Francisco man and his wife were part of a ring that brought women from the East Coast and pimped them out on a circuit of illicit Northern California brothels, authorities said.

Zhi Liu, 49, was due to enter a plea Monday to pimping, pandering and human trafficking charges in San Mateo County Superior Court, but didn't due to lack of a Mandarin interpreter. His wife Wei Guo, 51, remained on the run and wanted Monday, chief deputy district attorney Karen Guidotti said.

Liu and three Sacramento residents were arrested Thursday at the culmination of a five-month investigation that included the state Department of Justice and the FBI. Authorities said the ring brought Asian women to Northern California and then rotated them between brothels in Sacramento and San Mateo County.

Prosecutors say Liu, who went by the name Bob, ran a brothel from a San Bruno apartment and then moved the operation to a South San Francisco unit in May. He was behind bars in lieu of $100,000 bail and was due back in court Tuesday to face three counts each of pimping and pandering as well as one charge of human trafficking.

Liu's defense attorney didn't immediately respond to messages seeking comment on the charges.

Contact Joshua Melvin at 650-348-4335. Follow him at Twitter.com/melvinreport.