Scientists have discovered a large void in the Great Pyramid, or Khufu's Pyramid, on the Giza Plateau in Egypt, using radiography technology, Nature magazine reported.

The void, 30m in length and several metres high, was found through detection technologies and analyses, Nature reported on Thursday, adding that it is yet unclear what is inside the chamber.

Khufu's Pyramid was built during the fourth dynasty under Pharaoh Khufu, who reigned from 2509 to 2483 BC. Despite being one of the oldest and largest monuments in the world, there is no consensus about how it was constructed.

"To better understand its internal structure, we imaged the pyramid using muons, which are by-products of cosmic rays that are only partially absorbed by stone," the scientists reported in Nature.

"The resulting cosmic-ray muon radiography allows us to visualise the known and potentially unknown voids in the pyramid in a non-invasive way."

The study reported the discovery of the chamber of at least 30m in length, situated above the Grand Gallery of the pyramid.

According to the scientists, the discovery constitutes the first major inner structure found in the Great Pyramid since the 19th century.

"While there is currently no information about the role of this void, these findings show how modern particle physics can shed new light on the world's archaeological heritage," the scientists said.