The death of a woman at a central Whanganui property on Monday morning is being treated as "unexplained".
A police spokesperson said police were called to a Harrison St property around 9.15am following reports of a person being injured.
A St John spokesperson said one rapid response vehicle and two ambulances responded to the incident.
St John treated the woman and transported her to Whanganui Hospital in a critical condition.
Police said she died on the way to hospital.
Whanganui area commander Inspector Ross Grantham said at this time police were treating the woman's death as unexplained while they made inquiries to establish what had happened.
"The Harrison Street community will notice our staff in the neighbourhood while we examine the property and speak with people in the area," he said.