Theo Hayez, 18, disappeared while returning from a nightclub to his hostel in Byron Bay on the night of May 31, and is understood to have sent WhatsApp messages in the hours before he went missing.
Kai Riemer, professor of Information Technology and Organisation at the University of Sydney, told Xinhua news agency on Tuesday that WhatsApp would not have access to message content but would likely have access to metadata.
"WhatsApp is an encrypted service, so would not have access to actual message content, but they should have access to content about who communicates with whom, maybe their location if that is shared by their device and if the device was turned on at the time," Riemer said.
The teen's father Laurent Hayez travelled to Australia to assist in the search and has urged WhatsApp to do whatever they can to help locate him.
"We understand the politics about confidentiality and respect that - however, this is a question of providing assistance to a person in grave danger," the father told reporters.
WhatsApp has said they are assisting police with their enquiries.
"Our hearts go out to Theo Hayez and his family," it said in a statement.
"We understand the important work being carried out by law enforcement and are assisting them in accordance with applicable law and our terms of service."
( With inputs from IANS )