For three days, a three-year-old boy had been saying there was "a man with a light" outside his window at night.

But his parents assumed the man was just a figment of the boy's imagination. "I thought, obviously he's just had a bad dream," said his mother, children's author Melissa Rodrigues.

The boy's family used an old smartphone and an app called Salient Eye to capture the intruder.

On June 26, he woke them again.

"At 5.30 in the morning he let out an absolutely gut-wrenching scream from his room," Ms Rodrigues said. "I knew something wasn't right."