Authorities looking for a missing Belgian backpacker in northern NSW will shift their focus along a headland near Byron Bay after another fruitless day of searching.
Theo Hayez's distraught father Laurent made an emotional plea for help on Monday, 17 days after he was last seen leaving the holiday town's Cheeky Monkey's bar about 11pm on May 31.
He said he feared his son was in grave danger and begged for any information that could lead police to his whereabouts.
"Before I left Belgium I promised Theo's little brother Lucas that I would bring his brother home. Please, help me keep my promise to him," Mr Hayez told reporters through tears.
Theo used encrypted service Whatsapp the night he disappeared and Mr Hayez asked for help obtaining access to the messages.
WhatsApp confirmed it had provided all the information it has to police.
However the company is only able to access and disclose some data - which can include a user's name, last seen date, IP address and basic information - but not the encrypted content.
Dozens of people, including State Emergency Service volunteers and members of the public, on Tuesday returned to the area around Cape Byron Lighthouse where the last 'ping' from Theo's phone was recorded on June 1.
The search was suspended that evening with nothing of interest found, NSW Police said in a statement.
The operation will resume mid-morning on Wednesday with specialist police forces.
Theo had been preparing to return home after eight months travelling Australia.
Homicide detectives are helping the investigation along with Belgian authorities but police hold hope Theo is still alive.
More than $65,000 has been raised via a GoFundMe page for the Hayez family, part of which was used to help Laurent Hayez fly to Australia.
Mr Hayez arrived in the country late last week and has vowed to stay until his son is found.
Australian Associated Press