Detective Senior Sergeant Dave de Lange said police were treating the deaths as unexplained.
"We are keeping an open mind - anything is a possibility at this stage. We will know more when we get the [toxicology] results."
Residents in the Northcote street where the couple had lived for a year were stunned by their deaths.
Neighbour Tom Johnston said the couple - who he knew as Louis and Elaine - were excited about the holiday planned with their son and daughter-in-law, who were visiting from the family's native Hong Kong. The couple also had two adult children living in Auckland.
"What a shock, I can't believe it. I used to talk to him every day, he was very nice."
Chiu Ng had suffered from heart problems, Johnston said.
"She wasn't the best, she'd been in hospital and had three stents put in six months ago. But he was good."
A woman who identified herself as the owner of the motor lodge, but did not want to be named, said yesterday she was relieved police believed the couple died of natural causes.
"It's good for us, good for the family, good for everybody."
The fully-booked motel remained open during the police investigation and the room the couple died in had been released back to the owners on Friday night. However, the woman would not say what number it was or what would be done with the room.
"We have things in place that we are going to do, I don't want to say what those are."
Lodge owner Clinton Green previously told Hawke's Bay Today the couple were "really nice" people.