"On the other hand, as an architectural discovery, something we didn't know about the interior of the Great Pyramid, it's absolutely big news".
Analysis also shows the void connects with the burial chamber of the pharaoh Khufu whose remains inhabit this giant memorial site.
"What is unusual, for me, is to use those very, very small particles for a huge monument like the pyramid", says Tayoubi.
Scientists have discovered a big void in Khufu's Pyramid, the largest pyramid in Giza, Egypt. Researchers say they've discovered a new room inside the ancient structure.
To try and better understand what lies inside the pyramid, an worldwide team of researchers imaged the internal structure using subatomic particles called muons - by-products of cosmic rays which can penetrate stone.
At present, neither the particle physicists nor the world's Egyptologists have any idea just what objective the Big Void filled, nor what artefacts, if any, maybe sealed inside it.
Believed to have been erected as a tomb for the Fourth Dynasty Egyptian pharaoh Khufu (2589-2566 BC), the pyramid has always been known to contain four internal structures.More news: Man United get Jones boost ahead of Tottenham clash
The Verge laid out a succinct, easy to understand, and extremely radical-sounding explanation of muons: "Muons are produced when the cosmic rays that permeate our Universe and pummel our atmosphere break down - creating a kind of subatomic confetti that rains down on Earth at nearly the speed of light".
The presence of the void, dubbed the ScanPyramids Big Void, was confirmed using three different muon detection technologies over several months after first being spotted, the paper said. Scientists say the particles penetrate any material that made them the ideal tool to X-ray the pyramid with.
Tayoubi explains that his team installed sheets of muon-detecting film in a lower-level room of the pyramid known as the Queen's Chamber.
Experts, led by Mehdi Tayoubi, said they were "very confident" the results were correct.
Finding the new space was a happy accident, and the unexpected discovery could provide clues that will help archaeologists solve the pyramid's other mysteries.
Right now, there are no plans to enter the Great Pyramid to further investigate the void, because there is no way to get to it through the existing network of passages and chambers.
"It was hidden, I think, since the construction of the pyramid", Tayoubi added.