New documentary exposes the bizarre adoption mystery of Ukrainian Natalia Grace

A mysterious adoption more than a decade ago is sparking buzz about an upcoming documentary … a Ukrainian girl who allegedly tried to blend in as a young child and ended up with her new family. attempted murder.

Representative Beth Karas join us on “TMZ Live” as we deliver the scoop ahead of the first episode of id’s “The Curious Case of Natalia Grace” … which follows an American family who adopted Natalia Back in 2010, only to find out she was a lot older. For some years the parents believed she was not 8 years old…they were sure she was about 22 years old.

Beth says that Natalia repeatedly threatened her new family with knives and even tried to poison them.

Natalia’s child persona has people divided on whether she is a child or a fully grown one – she interacts with young children as if she were a peer but also displays an adult side.

Her story is often compared to the horror film “Orphan” … which came out a year before Natalia’s adoption and is based on a terrifyingly-similar story.