A woman accused of keeping an illegal immigrant as a servant at her upstate New York mansion says the housekeeper has become a prosecution witness in an effort to get legal status to remain in the United States.

But prosecutors say the woman, who faces a federal felony, kept her emigre servant overworked, underpaid and essentially captive for several years.

Both sides agree the housekeeper, identified in court papers only as V.M., a middle-aged widow from India, worked for Annie George, her late husband and six children for five years. Immigration investigators removed her in May 2011 after her son in India called the National Human Trafficking Resources Center, which says it has identified hundreds of similar U.S. cases.

Bradley Miles, executive director of the nonprofit Polaris Project, which runs the 24-hour phone service, said the most frequently reported type of labor trafficking the organization hears about on the hotline are domestic servitude cases.