How haunted is Old Parliament House?

At least, that's what some people who have attended the Museum of Australian Democracy's latest after-dark experience believe.

The Old Haunted House Experience sees Canberrans walk the halls of the national institution, armed with various ghost-hunting equipment including an EMF (electric magnetic field) reader and divining rods in search of the paranormal.

"We don't want to influence anyone. We don't want them to walk away from here thinking that we've told them that they're going to see a ghost, or that they will see one," Museum of Australian Democracy's volunteer and museum experience coordinator Trent Winter-Perry says.

"But by using the instruments, such as the divining rods, EMF readers, spirit boxes, etc, we're ghost hunting, basically.

"It gives a bit of credence to what we're doing and visitors can leave here having made up their own minds about whether they think the building is haunted or not by the readings that they get from these particular instruments."

According to Winter-Perry, an Old Parliament House-based supernatural belief is not completely unfounded.

Aside from the building being ranked in the top 35 most haunted buildings in the world by US publication Travel + Leisure last year, Winter-Perry says there have been unexplained sightings and events for almost as long as the building has been around.

One of the most well-known apparitions that security guards and other night-time attendees have claimed to have seen has been dubbed the Minister of Murder.

It's thought to be Thomas Ley, a former NSW state parliamentarian who transitioned into federal politics to become the minister of justice from 1922 to '25. It was during that time that he signed off on various death sentences.

However, it was his actions outside of parliament that were more intriguing. Ley was often surrounded by suspicions with many believing he was involved in some shady deals, particularly after a man who helped fund his election campaigns was found dead.

But it was a second man's death that would be the undoing for Ley. In March 1947, the former politician was convicted and sentenced to death for arranging the murder of John McBain Mudie - a barman who Ley believed was sleeping with his mistress. Ley was originally sentenced to death, but three days before he was due to be hanged, his sentence was commuted because he was deemed mentally unstable. He died a short time later in an asylum.

"When he came into federal politics, it was believed that he desired to become prime minister," Winter-Perry says.

"And as such, it is believed that he hangs around the government party room in this building, and often we can see his apparition appear late at night in that area."

But Winter-Perry's favourite unexplained story has to do with some wet footprints that have appeared outside of the old prime minister's suite after dark various times.

Grainy photographic evidence of the mysterious footprints - captured by a security guard in 2014 - is shown during the tour.

"It's appeared quite a number of times, and it could be a bit of a stretch, but it's believed that it's actually [former prime minister] Harold Holt trying to find his office," Winter-Perry says.

Then-prime minister Harold Holt disappeared while swimming off the Victorian coast in 1967.

It seems the number of ghostly inhabitants may just be growing. Winter-Perry says since the restoration works were completed following the fire set by protesters in 2021, several people have reported seeing an apparition of a man running through King's Hall out of the House of Representatives chamber.