Annie George kept Valsamma Mathai a virtual prisoner at a mansion in a suburb of Albany

A woman who had been charged with cheating an Indian household servant of hundreds of thousands of dollars in pay and keeping her a virtual prisoner at a mansion was found guilty on Friday of knowingly keeping the servant in the country illegally.

Annie George, the widow of a hotelier who died in a plane crash, had said she did not know Valsamma Mathai was in the United States illegally. She said she did not mistreat Ms. Mathai during the 5 1/2 years she worked in her 20,000-square foot home in a suburb of the State capitol, Albany.

Ms. Mathai had testified that she slept in a closet, worked long days without vacation, days off or sick time and was not allowed to leave the property, a palatial stone mansion on a cliff overlooking the Mohawk River.

Federal prosecutors said Ms. George owed Ms. Mathai $317,000, based on the minimum wage and overtime for the hours she worked. Ms. Mathai said she was paid only $26,000, much of which she sent to her family in India.

Ms. George was convicted of harbouring an illegal immigrant. She faces a penalty of up to five years in prison and a $2,50,000 fine at her July 9 sentencing. She remains free on bail.

A federal jury handed down its decision on Friday after deliberating since Thursday afternoon.

The case surfaced when one of Ms. Mathai’s sons in India, Shiju Mathai, called the National Human Trafficking Resources Center in 2011.