ST. CHARLES – A Chicago woman working at a massage parlor in St. Charles has been charged with prostitution after offering clients "extras" for more money, St. Charles Police Department spokesperson Paul McCurtain said.

Jing Zhang, 50, of the 200 block of West 23rd Street in Chicago, is due in Kane County Branch Court, 530 S. Randall Road, on March 28 on charges of prostitution and keeping a place of prostitution, both Class A misdemeanors.

Her arrest on March 7 stemmed from an anonymous letter the police department received from a concerned resident, McCurtain said. He said the citizen wrote that he went to Marigold Massage, 2075 Prairie St., and was offered extra services if he paid more.

Investigations began a follow-up, McCurtain said, and an officer agreed to go undercover. The officer, who was given cash for the assignment, received a massage from Zhang, who asked if he wanted to pay for additional services, McCurtain said.

The officer called the detectives on surveillance and advised the woman she was under arrest, McCurtain said.