The disappearance of pregnant Hamilton woman Rae Portman in June is now being treated as a homicide.
Ms Portman, 33, was last seen on June 20 when she drove her VW Passat from Hamilton to Auckland and checked into a Mt Albert motel.
She hasn't contacted her friends or family since then, nor accessed her bank accounts.
Police launched an appeal for anyone knowing her whereabouts earlier in September but now believe she is dead.
"The police investigation into the disappearance of Rae Portman is now being treated as a homicide," Detective Inspector Mark Gutry said.
"The elevation to a homicide is based on information from the public through the 0800 RaePortman and the Crimestoppers phone numbers.
"The public are encouraged to continue contacting police with any information they have, no matter how trivial they believe it is."
Ms Portman's mother Rebecca Norton made an emotional appeal to the public seeking information about her pregnant daughter two weeks ago, saying her situation was "every mother's worst nightmare".
A friend of Ms Portman was last week charged with stealing Ms Portman's car.
Three other people have been arrested on assault and drugs charges but police say they are not related to Ms Portman's disappearance.