Theo Hayez missing: Father of Belgian backpacker who vanished in Australia breaks down as he makes emotional plea for information

The father of missing teen Theo Hayez, who vanished while backpacking in Australia two weeks ago, has broken down in tears as he made an emotional plea for clues about his son’s whereabouts.

Laurent Hayez appealed for help at a press conference on Monday, saying Theo could be in "grave danger".

Local police have called the disappearance of the 18-year-old Belgian “baffling”. Drones are now being used in the search.

Theo disappeared after leaving a bar in Byron Bay late on May 31. He has not been seen or heard from since.

His father flew from Belgium to help with the search and has now made an appeal for help to access his son's encrypted WhatsApp account.

He told reporters: "We know that Theo used WhatsApp the night he disappeared.

We understand the politics about confidentiality and respect that.

"However, this is a question of providing assistance to a person in grave danger.”

He continued: “It is vital that investigators get access to Theo's WhatsApp account without delay.

“Every minute counts.”

Police superintendent Dave Roptell said WhatsApp's owner Facebook was being asked for access to the missing man's account.

Facebook did not immediately respond on Monday to a request for comment.

Police, told of the disappearance on June 6 after Hayez failed to check out of his hostel and could not be found, said they had narrowed the search to two areas near the centre of Byron Bay based on his last phone records.

Theo had been backpacking around Australia since November and was due to return to Belgium last week, it has been reported.

Additional reporting by agencies.