About 30 people have been searching each day. They have also searched the pines area around Alexandra, the banks of the Clutha River from Alexandra to the Roxburgh Dam, and used a jetboat to search the Clutha River.
Bates' family and friends have also helped with the search. A specialist dog team is assisting, and a drone has also been used.
Bates' father, John Bates, of Alexandra, said the family was grateful to all who were helping search. They were overwhelmed by the support and thanked the police, LandSar and members of the wider community who were continuing to search.
Alexandra residents were now being asked to help by ''keeping an eye out'' for Bates and search their garden sheds, garages and outbuildings on their properties, both in town and out of town, as it was not unusual for Bates to walk up to about 10km from Alexandra, Gibson said.
People are also being asked to contact police if they notice anything unusual in river or hill areas around Alexandra.
''There's nowhere that we don't want people to go; they [members of the public] are not going to be destroying any evidence. We just need people out there keeping an eye out. If you see something a little bit strange, or if you're [in the hills with your dog] and your dog acts a little bit funny, please contact us.''
Any businesses with CCTV cameras were also being asked to check them, particularly footage from Sunday, February 11 and Monday, February 12, Gibson said.
Bates, who completed a Bachelor of Commerce at the University of Otago, was also known to visit Dunedin and felt "very comfortable there'', so Dunedin residents were also being asked to check sheds and report any sightings of him, Gibson said.
Bates was thought to be on foot, but it was possible he could have used public transport to travel out of Alexandra, Gibson said.
Bates is described as being of slim build, about 180cm tall, with short to medium length brown hair and brown eyes.
He was wearing a grey hoodie, white T-shirt, dark shorts and sneakers.
Bates had a quiet personality, so would not necessarily be "out talking to people'', Gibson said.
He asked people to keep sharing Bates' photo and online posts about his search through social media.
"We need to keep him in the forefront of people's minds. We need to find him.''