A mum in the USA and her boyfriend are facing decades in jail after they locked up two children in their home for so long they were acting like cavemen.

Katie Koch, 34, and her partner Joel Manke, 38, from Milwaukee County, Wisconsin State, USA, face a total of 10 felony charges for chronic neglect and false imprisonment of two children, aged 7 and 9.

The pair were arrested after the children were spotted roaming around the streets at the Bluemound Heights neighbourhood naked and covered in blood and faeces on Thursday, 13th July.

The children reportedly broke a window in the house to escape, before climbing onto the air conditioning unit after which they jumped into the yard and headed for the street.

Neighbours Christine Eder and her husband Rick were the first ones to spot them.

Christine said: “I will never forget the look on those boys’ faces. The only word that comes to mind — bewildered.”

Rick added: “It looked like they were wearing wigs. When I got a closer look at them, I looked at my wife and tell her, that’s not costumes.

“It looked like they were hit with a belt. That was more terrifying than anything, seeing a child like that.”

Christine continued: “They had never been outside before. If they have been, it’s been a very long time.

“They were just walking different. Their hair looked like it had never been brushed, never been cut. They didn’t know the outside existed.

“That’s when you notice that something was wrong.

“In my opinion, they had never been outside before. They couldn’t believe what they were looking at.”

She explained that when they tried to talk to the children, they were met with confusion, after which she instantly alerted the police.

When officers came, Koch reportedly said the children ran away after they broke a window.

Police found out later that Manke had lived in the home since 2007, while Koch and the children moved in about four years ago.

Some of their neighbours, however, claimed they never saw the children during the time period.

Later investigations revealed that the children were essentially confined to their room for much of their lives.

The windows were boarded up and doors were locked from the outside, in what responding officers described as “a terrible hoarding situation” in which they could not see the floor.

Officials stated that the children were kept in such miserable conditions, that when brought in to protective custody their heads had to be shaved off because their hair was tangled with faeces.

Milwaukee County Assistant District Attorney Mallory Davis said: “These children have been horribly damaged from their mother’s actions.

“They are completely uneducated. They are not potty trained, even at their ages. They are, essentially at this point, unable to function in society.”

In court, the court commissioner set Koch’s bond for USD 30,000 [GBP 30,000] in cash, while Manke’s cash bail was set at USD 6,500 [GBP 5,000].

Their preliminary hearings are set for Wednesday, 26th July.

If convicted, each of them faces fines of USD 120,000 [GBP 92,000] and 43 and a half years in prison.

Koch faces an additional USD 20,000 [GBP 15,000] fine and 18 more months in prison for the two counts of misdemeanour.