Rae Portman's car was stolen and sold by her friend soon after the pregnant Hamilton woman was reported missing over two months ago, police say.
Ms Portman, 33, who police say is involved with the drug scene, was last seen on June 20 when she drove her VW Passat from Hamilton to Auckland and checked into a Mt Albert motel.
Police have grave fears for her safety as she has not contacted her family or friends, or accessed her bank accounts since then.
Detective Inspector Mark Gutry says a female friend of Ms Portman's appeared in Auckland District Court on Tuesday charged with the theft of Ms Portman's car.
Ms Portman dropped her car, which was worth about $2000, to an Auckland mechanic to be repaired on June 20.
On July 3, the day after Ms Portman was reported missing by her mother, the mechanic made a public appeal on Facebook for her family to collect the car.
A friend picked up the car a short time later, telling the mechanic she had permission from Ms Portman's family, but Det Insp Gutry says this was untrue.
The woman then allegedly sold the car for $1000.
She has been charged with theft of a vehicle and is due to reappear in court on November 20.
Ms Portman was not reported missing until the beginning of July because her mother was used to not hearing from her for weeks at a time.