9News understands the man is not connected to the family.
The man remains in custody, however no charges have been laid at this time.
The 51-year-old failed to return home that afternoon, sparking a huge police investigation led by the Missing Persons Squad.
Crews have previously been focusing their search efforts near the Canadian State Forest, including the Mount Clear region.
Investigators have also reviewed about 12,000 hours of CCTV footage and followed up more than 500 separate pieces of information during the investigation.
The 51-year-old is well-known in the community, with the family owning a car repair business and Samantha being heavily involved in the local theatre scene.
Detectives are continuing to appeal for anyone who has CCTV or dashcam footage and is yet to speak to police to come forward.
