A Chinese-born woman is suing her adoptive parents as well as multiple agencies after she was allegedly kept as a slave in a basement and suffered abuse for years as a child in New Hampshire.

Olivia Atkocaitis, now 19, filed the lawsuit in Merrimack County Superior Court against her New Boston parents, Denise and Thomas Atkocaitis, who also had three biological children of their own, NextShark reported.

Multiple agencies were named in the lawsuit for preventing the girl from getting the help she needed.

The local school district, the New Hampshire Division for Children, Youth and Families (DCYF), the New Boston Police Department and a Massachusetts adoption agency are among two dozen defendants named in the lawsuit filed Monday.

Adopted from China in 2004, Olivia joined the Atkocaitis family when she was 14 months old and allegedly suffered abuse from the age of 3, which started with her being tied to a metal column using a dog leash.

The adoptive parents are accused of confining the girl to a "dungeon" — an 8-by-8-foot room in the basement of a residence that was 4,300 square feet large and had four bedrooms.

The girl was fed maybe once a day and spent most of her time in the dungeon, which had only one window, as per the lawsuit. The siblings said their house would smell because Olivia had to use a bucket instead of a toilet.

The girl would only be allowed out of the dungeon to do chores and tend to the farm animals on their 27-acre property, as per the documents.

The couple's children studied in public schools while Olivia went to school only once.

"Her life was a nightmare, in that she was treated in the most vile fashion," Mike Lewis, Olivia's lawyer, told WMUR. "And as the lawsuit indicates, the people who should have protected her didn't. And it's shocking."

Although Olivia attempted to escape multiple times, the police reportedly brought her back to the Atkocaitis home, where the alleged abuse continued.

In one incident, one of the couple's children spoke to a school counselor and said the adopted girl, then 8 years old, was starved and whipped in the house. The sibling also said Olivia was pushed down the stairs.

The school then alerted the police and DCYF about the situation. But even after the police arrived and photographed the dungeon, Olivia continued living in the house and was abused for several years more.

"The police actually went into the home and documented the dungeon that Olivia was living in, but Olivia remained there for the next seven years," Lewis said.

The police department is currently denying allegations of failing to protect Olivia and said they played a role in removing her from the house.

However, Olivia's lawyer said she managed to escape through her own efforts.

"The implication that anybody but Olivia freed herself from that situation is demeaning," Lewis said. "Olivia literally dug herself out of that situation."

Representational image: Police car
Representational image (Source: Pixabay / fsHH)