A woman who in December fled to her native Cameroon after she was convicted in federal court in Greenbelt of enslaving and beating a young girl in Silver Spring has been captured, returned to the United States and is now serving her prison sentence, federal officials said.

With the help of Cameroonian authorities, Theresa Mubang, 42, was arrested in Cameroon on Thursday and expelled, said Manny Van Pelt, a spokesman for U.S. Immigration and Customs Enforcement.

U.S. officials flew Mubang to Brussels, then to Dulles International Airport, where she arrived Saturday, Van Pelt said.

In November, a U.S. District Court jury found Mubang guilty of involuntary servitude and harboring a juvenile for financial gain.

Mubang, a naturalized U.S. citizen, was convicted of forcing her victim, Evelyn Chumbow, to work for her as a domestic servant for two years in the late 1990s, beginning when the girl was 11.

According to trial testimony and federal prosecutors, Mubang beat Chumbow, now 18, with a high-heeled shoe, a metal broom handle, a cable and her fist.

When Mubang was convicted, Amy E. Pope, a trial attorney with the Justice Department's civil rights division, asked U.S. District Judge Deborah K. Chasanow to order that she be taken into custody immediately to prevent her from fleeing.

Mubang's attorney, Peter Goldman, said she needed time to arrange for the care of her two young children.

Chasanow agreed to let Mubang, who had surrendered her passport, remain free until she was sentenced, provided she be fitted with an electronic monitoring device.

Almost a month later, on Dec. 16, Mubang removed the electronic bracelet and fled her Silver Spring home, Van Pelt said. Mubang left her two children in the care of a severely mentally handicapped brother, authorities said.

Goldman declined to comment yesterday.

The United States has no extradition treaty with Cameroon. Agents from the State Department's Diplomatic Security Service at the U.S. Embassy in Cameroon depended on cooperation from Cameroonian officials to capture Mubang, Van Pelt said.

Federal authorities did not provide details about how they found her.

Mubang is part of what immigrant rights advocates say is a widespread problem involving the exploitation of domestic workers in the United States.

According to law enforcement officials and advocacy groups, thousands of women are recruited every year from impoverished countries to be live-in domestic workers in the United States. In October, a report by the Human Rights Center at the University of California at Berkeley and the Washington-based group Free the Slaves said that at least 10,000 people are working as forced laborers at any given time in this country.

Chumbow was not the first Cameroonian girl Mubang had abused and forced into servitude, according to federal prosecutors.

In the mid-1990s, Mubang abused and enslaved another Cameroonian girl, according to papers filed by federal prosecutors. No charges relating to that girl have been filed.