Chance has not been seen or heard from in 12 days since he drove south along Auckland's Southern Motorway towards Karaka.
Police say they are keeping an open mind about his disappearance but foul play remains a possibility.
It emerged on Wednesday there had reported sightings of his red Nissan Skyline in Waihi. Meanwhile a Facebook user claimed they had seen Chance in the local New World supermarket, in a post on a site dedicated to finding the missing man.
New World Waihi store manager Amandeep Chahal told the Weekend Herald he was alerted to a possible sighting of Chance in the supermarket by police at midday today.
A security guard was now looking through hundreds of hours of security camera footage to try to verify or rule out the sighting.
The sighting was posted on a Help Find Denver Facebook page set up after the 43-year-old went missing from Mairangi Bay in Auckland's North Shore on Sunday, February 24.
And in another apparent sighting, a woman wrote today that she saw Chance last week at the same supermarket and his distinctive red Nissan Skyline outside.
She also claimed to have seen Chance again at 11pm in Tauranga, but did not specify which day.
Her comments come as police say they can't rule out that a sighting in Waihi of Chance's car, registration LGH476, could be wrong.
Earlier today Detective Senior Sergeant Megan Goldie said CCTV footage showed two red Nissan Skylines travelling on the Southern Motorway a minute apart on that Sunday afternoon.
"The last confirmed sighting of [Denver's] vehicle was heading south on the Southern Motorway under the Penrose overbridge st 3.52pm on Sunday February 24th," Goldie said.
In a exclusive interview with NZ Herald's Focus: LIVE, Goldie said police could not rule out that CCTV footage of the car in Waihi at 5.30pm that day was the other vehicle and not Chance's.
"We are unable to conclusively say that the vehicle in Waihi is Denver's," she said.
"It could; be, but it also might not be."
There had been no positive sightings on Chance himself in Waihi, Goldie said. The car identified was "almost identical" to his Nissan Skyline.
While police were going door-to-door in Irwin Rd, Karaka - where Chance's cellphone pinged off a cell tower after 11pm that Sunday - Goldie said Waihi still remained an area of interest.
"We know that Denver had talked to his friends about purchasing property in the Waikino and Waihi areas," she said.
Goldie said there were a number of reasons Chance could be missing, and foul play was still a possibility.
"But we are keeping an open mind and making sure we cover all avenues," she said.
A Waihi real estate agent, who has three properties for sale in Waikino, said she had not been contacted by Chance or ever shown him through any homes.
Police sought CCTV footage from the Waikino Hotel in the Karangahake Gorge between Waihi and Paeroa but the footage automatically deleted every 48 hours.
One worker there had not heard of Chance and did not know he was missing.
In Paeroa, Caltex Service Station owners David and Sandra Milner, said police had asked for their CCTV footage on Wednesday.
The couple were shocked when they realised they knew Chance's mother Paula McGregor, who lives with Chance's stepfather at Hikutaia, between Paeroa and Thames.
Meanwhile on the Help Find Denver page today the administrators asked followers to search the Waihi to Whangamata road in case Chance had crashed his car off a bank.
"We are desperate to find him and encourage anyone with anything to let us know."
Goldie said Denver's disappearance wasn't reported immediately because "he is an adult and capable of looking after himself".
"The alarm wasn't raised until a couple of days had gone by.
"There was no cause for concern initially," she said.
The fact he hadn't made contact with his family and friends, and hadn't used his phone or bank accounts in the time elevated the concern.
Goldie said it was not regular behaviour for Chance to head away without letting anyone know.
"In the past if he was going overseas he would definitely let them know that he was going and that he would be away for a set period of time," she said.
"We just really encourage anybody that has any information on Denver, where he might be, where his car might be, to contact us."
She said no one had popped up in the investigation as being a real person on interest.
There was also no evidence as to why Chance may have been in the Karaka area.
Police continue to trawl through hours of CCTV footage as part of the investigation.
