On International Missing Children's Day on May 25, Mr Morcombe shares his experience as a parent whose child has vanished without a trace.

"The world is a different place for those who are constantly looking," Mr Morcombe said.

"You are looking and nothing will stop you from finding the answer.

"It sounds bizarre but that is the place you are forced to be in."

Daniel, 13 years old at the time, was playing with his brothers, picking passionfruit on their Sunshine Coast property.

Little did the Morcombe family know this would be the last memory they would have of Daniel alive.

With his parents at a work function on December 7, 2003, Daniel took a bus to the local shops to buy his parents a Christmas gift and get a hair cut.

As would be revealed eight years later, Daniel was waiting for the bus to return home, when Brett Peter Cowan lured him into his car. Cowan was convicted of his murder.

"As a parent, you feel like a failure," Mr Morcombe said.

"You don't want to go down that path of saying, well, I've got two kids, but by the way one is missing.

"You think to yourself, what have I done?"

Tragically, the Morcombe family's experience is not isolated.

Australia has 38,000 reported missing people annually with two-thirds of those under 18 years of age.

In 2022 alone, 17,000 missing children reports were made to police, and of those about 2,500 had been missing for more than three months.

Faced with the news of his son's disappearance, Mr Morcombe said he went into a state of "paranoia".

He would drive around on his own investigation, taking photos of number plates and when a visitor came to their house, he'd keep the glass they'd used for fingerprints, just in case.

"Your suspicions are heightened," Mr Morcombe said.

"You're on edge - everybody is a suspect."

Having answers, even in the face of tragedy, was better than only having questions, he said.

"The day that we found out that Daniel was deceased was a better day for us than not knowing where he was," Mr Morcombe said.

"When someone's missing, you have nowhere to go, you don't know if they're dead or alive.

"So, although it is terrible knowing we'll never see our little boy again, at least now we have a place to go see his grave and lay flowers."

IN OTHER NEWS:

Mr Morcombe said May 25 is a sad yet important day.

"We go to these events every year and even without knowing the people you can tell by the look in their eyes who the parents of missing children are," Mr Morcombe said.

"You wear a facial expression marked with eternal sadness."

This year, the National Missing Persons Coordination Centre, in partnership with the Daniel Morcombe Foundation, has released online resources to encourage parents to talk to their children about safe behaviour.