The team has made two visits to Eltham's Coronation Hotel recently.
One night when he was there Mr Sturmey heard so many footsteps outside in the hall that he couldn't sleep.
"I went out to tell somebody to stop it and there was no one there."
On another visit he spent the night in the hotel's only "haunted" room.
"The blankets were ripped off me and it felt like somebody was jumping up and down on the bed."
He was told that was usual for the room, and the suspect was a former proprietor, Jack, who didn't like males.
One of the investigators was pushed on the stairwell at the hotel, and the group brought in a medium who said the activity was "really angry and really strong".
WPI had also been working in Wanganui, and Mr Sturmey said it had strong evidence from the Whanganui Riverboats building at 1a Taupo Quay.
"We actually saw an apparition move from the back of the door to behind the boat."
He brought some photographs to show the Chronicle. They were taken at night with both an ordinary and a full spectrum camera and showed lines and spots of lights, and misty areas that he called "a manifestation".
Another photograph was taken with an ordinary camera at night in Paetaia Rd, near Waitotara. Mr Sturmey had heard there was a military camp there during the country's Land Wars. It showed a tree trunk and fence wires, with a shadowy shape he said most people thought was a little girl.
"There's a lot of activity going on in Wanganui, but a lot of people are just wanting to keep it under the radar."
One day he hoped to go to The Myrtles Plantation in Louisiana, said to be the most haunted house in the United States. The group is looking for sponsorship for that trip.
WPI has a website: www.wanganui
paranormalinvestigations.net