The Morcombes made the appeal at the Australian Centre To Counter Child Exploitation in Brisbane for International Missing Children’s Day on Thursday.

Bruce Morcombe said ordinary Australians needed to be the “eyes and ears of their police force” and report anything suspicious.

“Long-term missing children in Australia amount to two bus-loads of kids … we need to reunite these kids,” he said.

Denise Morcombe said she and her husband helped launch International Missing Children’s Day in Australia in 2009.

“It’s an important day for us to get the information out there for the missing children so all the families who have got an answer whether the child is deceased or found, the family does need an answer,” she said.

The couple’s 13-year-old son was abducted on December 7, 2003 on the Sunshine Coast while waiting for a bus to take him to a shopping centre to buy Christmas presents.

Daniel’s remains were not found until August 2011 following an elaborate undercover police operation that led to his killer being jailed for life.

The AFP, in partnership with the Daniel Morcombe Foundation, has released a suite of resources on its missing persons website to support parents in talking to their children about safe behaviour.

Australian Federal Police Assistant Commissioner Justine Gough said more than 17,000 missing persons reports relating to Australian children were filed last year.

She said it could be difficult to talk to children about how to stay safe, but those tough conversations could also help to protect them.

“We ask parents to remove friends or followers that you don’t know from your child’s and your own social media accounts and ensure all accounts are private and share photos only with people you know and trust,” she said.