The search for Belgian backpacker Theo Hayez involved one of the largest police investigations into a missing person in the NSW Northern Rivers region, his inquest has been told.
The second week of the inquest into the 18-year-old's disappearance in Byron Bay is hearing about police operations and some roadblocks that were faced in obtaining information.
The traveller was last seen being ejected from the Cheeky Monkey's bar at 11pm on 31 May, 2019.
Google data shows Theo looked up the route back to his hostel, but for unknown reasons walked in the opposite direction.
His cousin earlier told the court Theo was not a risk-taker, an adrenaline-seeker or a regular drinker, and it's ambiguous whether he was drunk before being kicked out of the bar.
The search for Belgian backpacker Theo Hayez involved one of the largest police investigations into a missing person in the NSW Northern Rivers region. Source: AAP
The subsequent search then included police officers, the State Emergency Service, family and volunteers from the community, underwater and from the air, counsel assisting the inquest Kirsten Edwards said on Monday.
Police's working theory is he tried to climb cliffs at Cosy Corner beach, fell and was swept out to sea. A hat he was wearing was found in bushland on the route he walked.
By the time the investigation was launched hostel guests were dispersed "all over the world," but were nonetheless followed up, and CCTV footage from the local area was obtained.
Ms Edwards pointed out certain barriers for detectives investigating a missing person not faced when a matter is deemed a crime, such as businesses having the power to decline requests for information if they want.
And police do not have the statutory power to search a person, home or campsite to find evidence solely in connection with a missing person.
Belgian investigators were contacted but a request for mutual assistance was declined, while the total process of such a process can take up to 18 months to complete, the court was told.
Mr Hayez's cousin Lisa Hayez was asked by police to access his computer data so they would not breach privacy legislation by gaining unauthorised access.
This was an unusual case of a missing person falling out of contact with family, said to be "highly out of character," Ms Edwards said.
"Sadly it could be argued that legislation has not kept pace with these developments involving technology," she said.
"We understand ... there have been huge advances in criminal investigations but missing persons investigations has not received the same focus and powers"
Technology companies such as Google and Spotify have their own company policies for sharing data and are often dictated by strict European privacy laws.
The NSW Coroner's Court in Byron Bay was then closed on Monday for a more detailed chronology of how data evidence was obtained, so sensitive information would not be revealed.
The inquest continues.
