After vanishing from a campsite 19 days ago, Cleo Smith has been found “alive and well” in a locked house in Western Australia.

After breaking into the Carnarvan home at about 1am on Wednesday, police found the little girl in one of the rooms.

“Cleo is alive and well,” Deputy Commissioner Coll Blanch said in a statement.

“They found little Cleo in one of the rooms.

“One of the officers picked her up in his arms and asked her, ‘What’s your name?’.

“She said, ‘My name is Cleo’.”

She was reunited with her family a short while later.

“This is the outcome we all hoped and prayed for,” Blanch said.

“It’s the outcome we’ve achieved because of some incredible police work.

“I want to thank Cleo’s parents, the Western Australian community and the many volunteers.

“And of course, I want to thank my colleagues in the Western Australia Police Force.”

A Carnarvon man has been taken into custody and is currently being questioned by detectives.

Cleo first disappeared while her family was camping at the Blowholes campsite near Carnarvon.

Since then, police have searched the family’s home, reviewed CCTV footage, scoured the dark web, and enlisted the assistance of volunteers and interstate and US authorities.

A $1 million reward was previously announced by the WA government for any information leading to Cleo’s location.

Image: 7News

Criminologist Xxanthe Mallett said the news was a “miracle” as “it’s highly unusual to find an abducted child alive and well after so long”.

“I’ve got to say that I have been expecting the worst, we’re up to day 19 now,” she told Sunrise on Wednesday.

But, she believes the man currently being questioned is likely linked to Cleo and her family.

“We always felt that this was something targeted,” she said.

“I imagine that they will know Cleo, there will be some link to Cleo and that’s how they will have tracked them down.”

Image: 7News