A father who adopted a 'child' that turned out to be a 22-year-old woman has broken down in a full-on fit of rage.

The man, whose family adopted who they thought was a Ukrainian child with dwarfism back in 2010, later claimed that she was an 'adult sociopath masquerading as a child'.

In a new documentary covering all the details behind the bizarre and harrowing case, the dad uncontrollably cries and punches the floor in a crazed fury screaming that his family were 'all abused' by her.

Michael Barnett has appeared in a brand-new trailer for the upcoming documentary series, The Curious Case of Natalia Grace, which is set to hit our screens later this month on 29 May.

The three-part series follows the likes of Michael and his wife, Kristine, who first adopted Natalia Grace back in 2010 under the impression they were welcoming a six-year-old child into their home.

Investigation Discovery

However, suspicions started to raise after the couple claimed Natalia grew violent and threatened the family's lives.

The parents said that Natalia 'threatened to stab' their children while living with them in Layfette, Indiana.

"She tried to poison and kill my wife," Michael continued, "one night, I opened my eyes and Natalia is standing at the foot of the bed with a knife in her hand."

Their biological son, Jake, also corroborated such claims, stating: "I definitely didn't feel safe around Natalia."

After such reports, the family then began to grow doubtful over Natalia's identity and suspected that she was actually an adult illegally posing as a child.

Michael and Kristine decided to take action and petitioned a probate court to amend Natalia's official birth year back 14 years.

The petition was granted back in 2012, which legally changed Natalia's age from just nine years old to 23.

After that, the family decided to take off to Canada and left the 23-year-old back to fend for herself in Layfette after giving her her own apartment.

But this was by no means the end to the ordeal as the Barnetts were subsequently landed with some pretty serious neglect charges for allegedly abandoning a child.

Investigation Discovery

However, Michael and Kristine pushed back and instead claimed they were victims of fraud.

Now, the parents are able to tell their side of the story and they haven't held back.

Michael, who was only recently acquitted of the neglect charges, warned viewers in the action-packed trailer that they would be getting the 'truth' about the high-profile case but they 'might not like the truth.'

He can also be seen visibly shaken as he violently slammed his fists into the ground after opening up about the traumatic situation with his adoptive daughter.

The clip sees the man wailing: "We were all abused! I hate this!"

The first part of The Curious Case of Natalia Grace will be available to watch on on Investigation Discovery later this month on 29 May.