A purported 'vast underground city' in Egypt is tens of thousands of years older than the Giza pyramids, scientists have shockingly claimed.

If true, it would turn Egyptian - and human - history on its head, though independent experts have called it 'outlandish' and 'crazy talk.'

Last week, researchers in Italy presented bombshell research which claimed to have discovered multi-thousand-foot tall wells and chambers underground beneath the Khafre Pyramid. 

The Giza pyramids are believed to have been built around 4,500 years ago and considered a remarkable feat given their immense scale and the precision of their construction, which remains a mystery for the time period.

However, researchers behind the new study claim that the hidden structures, spanning 4,000 feet, are approximately 38,000 years old — which predates the oldest known man-made structure of its kind by tens of thousands of years.

The team has based these claims on ancient Egyptian text that they interpreted as historical records of a pre-existing civilization that was destroyed during a cataclysmic event.

Professor Lawrence Conyers, a radar expert at the University of Denver who focuses on archaeology and was not involved in the study, told DailyMail.com: 'That is a really outlandish idea.'

He added that at that time in human history people 'were mostly living in caves' 38,000 years ago. 'People did not start living in what we now call cities until about 9,000 years ago,' he said. 'There were a few large villages before that but those only go back a few thousand years from that time.'

Not only have the claims been criticized by scientists, but also the state of Egypt itself.

Dr Zahi Hawass, Egypt's former minister of antiquities, told The National the entire study was 'completely wrong' and lacked any scientific basis. 

The work by Corrado Malanga from Italy's University of Pisa, Filippo Biondi with the University of Strathclyde in Scotland and Egyptologist Armando Mei has not yet been published in a scientific journal for the review of independent experts.

The team has held two press conferences in Italy to discuss the research.

They claim to have identified the hidden structures using radar pulses to create high-resolution images deep into the ground beneath the structures, the same way sonar radar is used to map the ocean's depths.