Mr Sergi has not been seen since around 11.30pm on March 19.

After local inquiries yielded no result, emergency services began a search of his property.

A search specialist from Goulburn arrived on the scene to co-ordinate the search on March 21 in collaboration with police, SES and Fire and Rescue NSW including PolAir.

Chief Inspector John Wadsworth said police were concerned for Mr Sergi and urged anyone with information to contact Crime Stoppers at 1800 333 000.

"This behaviour is very unusual and is of great concern," he said.

"As a result ... we are appealing for anyone with information to come forward."

He added that police currently had no reason to suspect criminal activity.

Chief Inspector Wadsworth said that there was no need for community or civilian volunteers to assist at this stage.

"Due to great assistance from the family, we haven't had to widen our search," he said.

"The search co-ordinator is specifically trained in these kinds of things."

Anyone with information on Mr Sergi's whereabouts is strongly encouraged to contact Crime Stoppers at 1800 333 000. Anonymous reporting is available.