Mark Wallbank, 56, founded Paranormal New Zealand in 1984 and has "always been into ghosts and UFOs".
"I've always been into the paranormal. Especially the unexplained mysteries out there. Because they were unexplained, that fascinated me more.
"We sort of straddle that line of believer and sceptic as well.
"So we're kind of in the middle, we're waiting for things to happen, and things do happen.
"And it's up to us to try and figure it out."
Wallbank and his team of seven investigators have camped out in haunted houses, searched for ghosts across New Zealand and travelled to Australia, the UK and Hawaii in pursuit of supernatural stories.
"We're not ghost hunters, we're not ghostbusters, we're not exorcists or anything like that.
"None of us in the team are sort of religious in any way, we don't bring any of that. We're basically just a bunch of people that have an interest."
Wallbank is the author of Haunted Auckland and is currently working on his fifth book which has a working title of Haunted South.
He wants people to send him their credible ghost stories to add to the project.
"I've just had so much come in - it's just incredible.
"And I've been talking to people via messenger and it's just been fascinating.
"The stories are incredible."
"I've covered things like Ballantynes, the big fire. Since then there's been a lot of activity in the building."
He has also investigated phenomena at the former United Services Hotel building in Cathedral Square, Christchurch Hospital and the Riccarton Hotel.
"They've (United Services Hotel building) had all sorts of experiences with people being shoved awake in their sleep, shadow figures in the hallways, glasses flying off shelves.
"There was one guy who was knocked down by something invisible that was running down the hallway."
Wallbank said there had also been a number of paranormal sightings at Bottle Lake Forest Park.
"People being chased by shadow figures and just sort of unseen.
"People walking the dogs and the dogs will start reacting and barking and running away, trying to pull the lead, trying to get away out of fear."
He said ghost stories have been around for thousands of years.
"Nobody really knows the true answers and the facts.
"While paranormal investigators and researchers have our theories, opinions, and findings, sceptics and the scientific community will have their theories and opinions as well.
"But neither are right. They're just opinions and theories."
Wallbank’s busy compiling the stories and aims to release Haunted South in November.
- For more information visit hauntedauckland.com.
- By Geoff Sloan, made with the support of NZ On Air
