Detective Senior Sergeant Dave de Lange said there was no indication at this stage how the couple died.
A post mortem examination was carried out today, and a police spokeswoman said the results won't be known for "a couple of weeks".
Mr de Lange said police will be "keeping an open mind" as to how they died.
A scene examination was completed this afternoon and police have spoken to the couple's son and his wife, as well as other people who were at the motel.
"It may take some time to establish the cause of death and until we get further information from the post mortem, including toxicology test results, we cannot confirm what direction this investigation will take," Mr de Lange said.
The police spokeswoman added that the couple's son and daughter-in-law are still in Napier and "understandably very upset by it all". They have been offered help by Victim Support.
Deco City Motor Lodge owner Clinton Green told Hawke's Bay Today the son and his wife were still staying at the motel.
They were holding up "as well as can be expected" given the circumstances, but he did not want to comment further "for the family - and they're still here - and so I won't be making any comment".
When told police could not yet confirm what direction their investigation was taking, he said: "I'd have to back that up. I think they're going along the right track. Any comments that could jeopardise something further ... I don't want to do that."
Police say the couple's names will not be released until all family have been notified.
