Houston - A Houston-area couple who pleaded guilty to federal charges related to forcing a Nigerian woman to work nearly 20 hours taking care of their home and five children without pay for two years was ordered Friday to pay her more than $121 000 in restitution.

Chudy Nsobundu, 57, and his wife Sandra Nsobundu, 49, also were sentenced by US District Judge Nancy Atlas to seven months in jail and seven months of home confinement, plus three years on probation.

The naturalised US. citizens originally from Nigeria recruited the woman there with the promise of a $100 monthly wage. Instead, authorities say they abused her physically and verbally while she worked at their home in the Houston suburb of Katy from September 2013 to October 2015.

Chudy Nsobundu in 2016 pleaded guilty to visa fraud while his wife pleaded guilty to unlawful conduct with respect to documents in furtherance of forced labor.

According to court documents, the nanny would work every day from 05:30 to 01:00, couldn't take breaks and had to eat leftovers and not fresh food, including being forced to only drink milk left in bowls in which the children had eaten cereal. She also couldn't take hot showers.

Authorities said the Nsobundus prevented the nanny from leaving their employment by keeping her passport and by threatening her with physical and mental abuse.

The nanny reached out for help and was rescued following a tip to the National Human Trafficking Resource Centre. Her name has not been released.

Prosecutors say the couple knowingly caused a false visa application for the victim to be submitted to the Department of State with numerous pieces of false information.

The woman's date of birth was incorrect on the application, listing her 20 years older than she was, said she was married when she was not, incorrectly indicated the purpose of her travel was to attend a niece's graduation and falsely identified her in a letter that Chudy Nsobundu was her brother. Prosecutors also said he made false representations under oath on the visa application to increase the chances that the application would be accepted and to hide the fact she'd be working for his family as a housemaid and nanny under conditions that violated US labor laws.

Federal prosecutors said Sandra Nsobundu took the nanny to the US Embassy in Lagos, Nigeria, to obtain her visa and provided her with a letter indicating she didn't speak English well, that she was to attend a family graduation and gave her a picture of her husband with instructions that she tell embassy officials he was the nanny's brother and that she was married. The nanny's husband listed on the visa application actually was the Nsobundus' driver in Nigeria.