A 36-strong team of ghosthunters say they have no doubt a former RAF base in north Wales is haunted after spending Saturday night there.
Maes Artro was a training base for RAF Llanbedr in 1941
Members of the Club Zero Ghost Group stayed up around the clock to monitor any spooky goings-on at Maes Artro in Snowdonia, now a heritage museum.
It has become a magnet for paranormal investigators from across the UK.
Owner Malcolm Green believes the ghosts of two RAF men roam the site, a fighter training base during World War II.
Club Zero was formed in Stockport, near Manchester, a year ago.
Member Christopher Cave said they saw unexplained shadows, the "ghost" of a dog and heard voices.
"We were up all night. There is definitely paranormal activity there and we are going to back for a full weekend in September to try and get it all covered.
"We set up infra-red and digital night cameras and digital and analogue sound equipment.
"We will now review all the tapes."
Fellow member Paul Prole said it was the first investigation for some members of the club, drawn from
all walks of life.
"We've got a few sceptics on our team and we've got people who totally believe in ghosts," he said.
"It's a serious matter to us because there are so many reports and sightings I don't think you can dismiss it totally
"It's not that glamorous really - we just sit in a building in the dark and wait for something to happen.
"Maes Artro is a former RAF base and the staff there have experienced quite a lot of unexplained things.
"There's a lot of people who died in training crashes there."
The former officers' mess forms part of the museum
Owner Mr Green said he was sure the place was haunted.
"We've been here a number of years and initially it was just things like putting a pencil down and then it would disappear.
"One night someone stayed in the building and was woken by chairs moving yet he was there on his own. He would not go back into the building again.
"Word has spread and we've had ghosthunters from all over."
He believes the ghosts of two airmen are responsible for most of the eerie events.
"It's not frightening - they have a sense of fun and sometimes make a nuisance," he added.