AN EGYPT researcher revealed a "strange door" found inside the subterranean chamber of the Great Pyramid of Giza had been explored by investigators.

Located on the Giza Plateau, the Great Pyramid is believed to have been constructed during the Fourth Dynasty for the Pharaoh Khufu. One of the Seven Wonders of the Ancient World, it is the only one still largely intact and is believed to have been constructed more than 4,500 years ago. There are three known chambers inside – the lowest was cut into the bedrock upon which the pyramid was built.

And author Ben van Kerkwyk, who runs YouTube channel ‘UnchartedX,’ was granted private access to film inside the ancient monument for two hours.

During the tour, Mr van Kerkwyk broke away from the main group to head down the passageway and explore the mysterious chamber at the bottom of the pyramid.

He said: “Everybody was heading up into the Grand Gallery and I made the decision to take the opportunity and shoot down to the subterranean chamber.

“This is looking back up at the descending passageway to what would have been the original entrance.

Inside the Great Pyramid of Giza (Image: GETTY)

A passageway in the subterranean chamber (Image: YOUTUBE)

“If you look closely you will see the cavity and the roof – that’s where the hidden lintel block was and that chamber is blocked up by three massive granite blocks that are in the passage.

“The passageway from there descends 87 metres down to the subterranean chamber.

“It’s unerringly straight, an incredible bit of engineering.”

The researcher headed into the subterranean chamber, which was filled with equipment used by the team who uncovered the mystery voids of the Great Pyramid in 2017.

But he also spotted another interesting opening.

A deep passage was shown during the video (Image: YOUTUBE)

Mr van Kerkwyk added: “Notice at the bottom there are no lights.

“There is still a lot of equipment down at the bottom from the ScanPyramids project which is ongoing.

“It’s essentially cosmic ray detectors looking for voids inside the structure.

“This is the massive subterranean chamber though, as deep as it goes.

“There is also this strange door that leads to a very odd little passage."

Great pyramid voids (Image: GETTY)

Mr van Kerkwyk said he had been inside the small opening before, claiming it had been blocked off since.

He continued in December: “When I last visited there was no door here and a couple of us crawled all the way down the passageway.

“It just ends and you have to back out.

"It doesn’t seem to go anywhere. Someone on our trip was banging on the wall.”

In 2015, the ScanPyramids project was launched to provide several non-invasive and non-destructive techniques which may help to provide a better understanding of the Great Pyramid’s structure.

The chamber was full of equipment (Image: YOUTUBE)

After two years of work, French experts announced the discovery of the “Big Void,” a 30-metre previously unknown cavity located above the Grand Gallery, but there has been no development since.

But Peter James, author of ‘Saving the Pyramids: Twenty First Century Engineering and Egypt's Ancient Monuments,’ believes there are many more to be found.

He previously told Express.co.uk: “As massive as the Great Pyramid is, it is structurally very sound and I’m sure there are holes and voids in there which are part of that.

“As they went up, they would have got to a point where they put support beams in, which would have created gaps.

“They would have left these empty or filled them with a material that is a different density to the outside.

“I’m sure there will be more similar discoveries in the future.”

Video can be accessed at source link below