“A vast underground city”, which stretches more than 6,500 feet directly underneath the Pyramids of Giza, making them 10 times larger than the pyramids themselves, has been uncovered by the researchers from Italy and Scotland.

The researchers’ claim – which many experts claim to have already debunked – comes from a study that used radar pulses to create high-resolution images deep into the ground beneath the structures, which is the same way sonar radar is used to map the depths of the ocean, reported Daily Mail.

Eight vertical cylinder-shaped structures extending more than 2,100 feet below the pyramid and more unknown structures 4,000 feet deeper have been found by the paper, which has not been peer-reviewed by independent experts.

Findings have been described as “groundbreaking” by a press release and if true could rewrite the history of ancient Egypt. However, independent experts have raised serious concerns about the study.

Professor Lawrence Conyers, who is a radar expert at the University of Denver who focuses on archaeology, told Daily Mail that it is not possible for the technology to penetrate that deeply into the ground, making the idea of an underground city “a huge exaggeration.”

It is conceivable there are small structures, such as shafts and chambers, beneath the pyramids that existed before they were built because the site was “special to ancient people”, the professor said.

Additionally, he highlighted how “the Mayans and other people in ancient Mesoamerica often built pyramids on top of the entrances of caves or caverns that had ceremonial meaning to them.”