Searchers on foot were checking sheds, outbuilding, gullies, under bushes and trees, including some areas previously searched, he said.
Earlier this week the Police eagle helicopter with thermal imaging capabilities was also involved in the search but failed to detect anything of interest, he said.
Police were continuing to receive calls about possible sightings in Mount Maunganui, Rotorua and Whakatane, some of which had been discounted after further investigation.
Owen said the search efforts and support from the local community was "outstanding".
"We couldn't do what do without them," he said.
Mohi, who suffers from dementia, had not been in contact with family since Monday when he went on his daily one to two-hour stroll from his Church Rd homestead at midday.
Ronnie Tapsell-Walters, Mohi's eldest granddaughter, said her koro's disappearance was out of character and she and her family were praying for his safe return.
"We know we're getting to the nitty-gritty side of the search and time is of the essence," she told the Bay of Plenty Times yesterday. "Fortunately it hasn't been too cold at nights, which was our big concern, and hopefully our koro has some shelter and shade to keep cool and he's resting up somewhere.
"We can't give up. There are still a lot of people searching for our koro, including some searching on their own. We're all keeping the faith he will be found," he said.
Tapsell-Walters said she and other whānau had little sleep since her koro went Missing but were determined to keep going, and their prayer sessions had given them strength.
"It's very concerning but we're realistic and have made our volunteers aware of what they may be dealing with," she said.
Mohi is described to be about 182cm in height, with a very slight build.
He was last seen wearing a dark coloured blue and white checked shirt, dark grey or black long pants and older-style blue coloured jandals.
If anyone sees Mohi, or someone fitting this description, they are encouraged to take a photograph and contact Tauranga Police as soon as possible on 07 577 4300.