IT’S a search that’s gone on for centuries.

In May 1933, the Inverness Courier reported a local couple seeing “an enormous animal rolling and plunging on the surface” of Loch Ness.

Nessie was born. Or, rather, the quest to find Nessie was born.

However, reports of a monster inhabiting Loch Ness date even further back to ancient times.

Local stone carvings from Pictish times portray a mysterious beast with flippers. The first written account appears in a biography of St Columba from 565 AD. According to that work, the monster bit a swimmer and was prepared to attack another man when Columba intervened, ordering the beast to “go back”.

It obeyed, and over the centuries only occasional sightings were reported. Many of these alleged encounters seemed inspired by Scottish folklore, which abounds with mythical water creatures.

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Steeped in equal helpings of mystery and controversy, still no one has been able to prove the monster actually exists.

Maybe that’s because there’s a whole different dimension involved. It seems Nessie’s story has taken on a new twist.

One expert claims the monster could spend most of its time hiding in a parallel universe, a bit like in the hit Netflix show Stranger Things.

In Stranger Things, a band of heroes face off against creatures from a pocket universe known as the Upside Down, and Scottish paranormal investigator Ron Halliday believes this could be a clue as to where Nessie disappears. He thinks this is why there hasn’t been actual evidence found of the beast.

Halliday, 72, explained: “Scientists have suggested there could be other universes. And somehow our world interacts with these other worlds through portals.

“With the Loch Ness monster, people could be seeing a dinosaur that existed in the past. They may see something that looks solid but isn’t actually in our world. That can spread across a whole range of things, such as UFO sightings.”

Halliday is also an expert in UFO sightings. Coincidentally, Scotland has been recorded as a hotbed of UFO activity – particularly in Stirlingshire, where Halliday lives.

He added: “Some people are more psychic than others. They can pick up these experiences while others may not. It’s possible that some may walk into these portals without realising it, then they can see these things. They are having genuine experiences. In a way, this is speculation. But to my mind, it does provide an explanation to a whole range of paranormal phenomena.”

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This theory differs from the one which recently resurfaced.

A 2007 report gained notoriety after it suggested that the giant beast could actually just be a huge frog.

In 2005, a team from United States-based SeaTrepid Inc performed a full deep-water scan of the loch, in the hopes of finding the mysterious Nessie.

But all they found was a frog – living at 325 feet below the water.

Obviously they were looking in the wrong dimension.

Is truth stranger than fiction after all?