The Schonell Theatre at the University of Queensland has been a part of the 100-year-old institution since 1970, but some supernatural elements of the theatre may be even older.

The Centenary celebrations of the University of Queensland are being held at the St Lucia campus this weekend, and those who undertake a 'Behind the Curtain' tour of the Schonell may catch a glimpse of the Schonell's resident spirit, Sophea.

Debbie Haddleton, Schonell Theatre Cinema and Venue Promoter, heard numerous stories about the ghost when she started asking around about the history of the theatre.

"The story of a spirit in the Schonell came up over and over again," she says to 612 ABC Brisbane's Anne O'Keeffe.

"The cleaning supervisor, the manager, some builders, the maintenance man all told me stories about having encounters with this ghost."

There have been six sightings of the ghost, who wears an old-fashioned long dress and appears as a real 'flesh-and-blood' human.

Ross Martin, the Schonell's manager, has had an especially spooky experience with Sophea, Deb reports.

"Where we are right now, quite a few years ago," she says, standing in the Schonell's Theatre One,"the manager - who I would say definitely doesn't believe in spirits - was standing here with another gentleman after the show (they were just waiting for everyone to leave) and a woman walked past just over here and walked behind them and into that dressing room over there, so they waited for her to come back out again and she didn't.

"That dressing room doesn't have any other exits," Debbie finishes pointedly.

Cleaning staff have also felt the presence of a ghost.

"Verna the cleaner sees her as a very cheeky and good sort of presence," Debbie says.

"Verna will be cleaning up in Theatre Two downstairs, and she'll clean up a piece of paper and then five minutes later it will be back there again, and she'll clean it up again and it'll be back.

"She said [to the spirit], 'Just stop it!' and it did, it stopped."

The good news for fearful movie-goers is that they're unlikely to run into Sophea anytime soon.

"We want to assure our patrons that this only happens after everybody's gone home," Debbie laughs.

The University of Queensland's Centenary Celebration Day (including the 'Behind the Curtain' tours of the Schonell) will be held on Sunday 18 April, from 9am to 6.30pm.

As part of the celebrations, 612 ABC Brisbane's Warren Boland will be broadcasting live in the Great Court from 10am -12pm.