A controversial scientific paper that claimed to have detected vast hidden structures beneath Egypt’s Great Pyramids has been formally retracted, dealing a major blow to one of the most extraordinary recent claims about the Giza complex.
The study, published in the journal Remote Sensing in 2022 by researchers Filippo Biondi and Corrado Malanga, claimed that a radar-based technique could reveal previously unknown structures inside and beneath the Great Pyramid of Giza.
The researchers later extended similar claims to the nearby Pyramid of Khafre, arguing that their analysis pointed to enormous underground structures, including shafts, chambers, corridors and what they described as a possible underground city.
Remote Sensing retracted the original paper on August 10, 2026, after an editorial investigation concluded that it contained “serious methodological flaws and statistical errors” that undermined its scientific conclusions. The authors disagreed with the decision.
What did the retracted study claim?
The original 2022 paper focused on the Great Pyramid, also known as the Pyramids of Khufu or Khnum-Khufu.
Biondi and Malanga proposed a technique called synthetic aperture radar Doppler tomography. Instead of attempting to transmit radar directly through the massive limestone structure, the researchers analyzed tiny movements associated with the pyramid and its surroundings.
They argued that these micro-movements could be processed to reconstruct three-dimensional information about structures inside and beneath the pyramid.
The paper claimed that the method produced high-resolution images revealing previously unknown features inside the monument.
What did the researchers later claim about the Pyramids of Khafre?
The Khafre claims generated far more attention.
In 2025, Biondi and Malanga said their technique had identified enormous structures beneath the Pyramid of Khafre, including eight large, cylindrical structures extending more than 2,100 feet underground.
They also described additional features at greater depths, including chambers, corridors and other geometric formations.
The researchers presented these findings as evidence of a massive subterranean complex beneath the Giza plateau.
Some online reports subsequently transformed those claims into descriptions of an ancient “underground city” thousands of feet beneath the pyramids.
But the evidence for such a city was never established through conventional archaeological excavation or independently verified imaging.
How was the alleged underground city supposedly detected?
The researchers relied on radar observations and their interpretation of tiny surface or structural movements.
Their method analyzed Doppler information from synthetic aperture radar observations, which they argued could provide information about the internal structure of the pyramids.
In the original paper, the researchers described the approach as a form of tomographic imaging capable of reconstructing three-dimensional features.
That is an extraordinary claim because conventional satellite-based synthetic aperture radar is primarily designed to observe surfaces and changes on or near them. It is not generally treated as a technology capable of producing detailed images of enormous underground structures thousands of feet below solid rock.
The retraction now puts the scientific basis of the original technique under much greater scrutiny.
Why was the paper retracted?
Remote Sensing said a reader raised concerns about the paper’s methodology after publication.
The journal then conducted an investigation involving its editorial office and board.
According to the formal retraction notice, the investigation confirmed “serious methodological flaws and statistical errors” that were considered serious enough to undermine the paper’s scientific conclusions.
The journal therefore decided to retract the article under its retraction policy. The decision was approved by the journal’s editor-in-chief.
The authors were informed of the decision and formally disagreed with it.
Does the retraction prove there is nothing beneath the pyramids?
No.
This distinction is important.
The retraction means the particular scientific paper and its conclusions are no longer considered reliable by the journal that published it. It does not prove that there are no undiscovered chambers, cavities or other archaeological features beneath the Giza plateau.
Archaeologists already know that the pyramids and surrounding area contain complex internal and underground features.
The question is whether the enormous structures claimed by Biondi and Malanga actually exist.
The retracted study cannot be used as reliable evidence that they do.
Why were scientists skeptical in the first place?
The claimed depth and scale were major reasons for skepticism.
The idea that satellite radar observations could reveal detailed structures more than 2,000 feet below a massive ancient monument challenged established assumptions about how radar interacts with solid materials.
Critics argued that the researchers were interpreting indirect signals as if they were direct images of underground architecture.
There was also a major validation problem. Extraordinary claims about enormous chambers, shafts and an underground settlement require independent observations using techniques capable of confirming the structures.
Without that validation, unusual patterns in remote-sensing data cannot automatically be interpreted as buildings.
What is synthetic aperture radar?
Synthetic aperture radar, or SAR, is a remote-sensing technology that uses radar signals to create detailed images of Earth’s surface.
Unlike ordinary optical satellite imagery, SAR can operate through clouds and in darkness because it does not depend on visible light.
It is widely used for mapping terrain, monitoring earthquakes, tracking land deformation, observing glaciers and studying changes in infrastructure.
The crucial issue in the Giza controversy is penetration.
Radar can interact with surfaces and, depending on the frequency and material, penetrate certain materials to limited depths. But that is very different from routinely producing detailed three-dimensional images of enormous structures thousands of feet underground.
That distinction sits at the heart of the criticism surrounding the claims.
What did the original paper say about the Great Pyramid?
The 2022 paper acknowledged the basic problem that conventional SAR has poor penetration into solid bodies.
The authors proposed getting around that limitation by analyzing micro-movements generated by background seismic activity and using Doppler information to infer structures beneath the surface.
They described the resulting approach as allowing the pyramid to become effectively “transparent” in the micro-movement domain.
The paper claimed that this enabled the reconstruction of internal objects and previously undiscovered structures.
The journal’s subsequent investigation, however, concluded that methodological and statistical problems undermined those scientific conclusions.
What about the famous ‘Big Void’?
The researchers also connected their work to the “Big Void,” a large cavity detected inside the Great Pyramid by the ScanPyramids project.
The Big Void is a real archaeological discovery, identified using muon radiography, a technique that uses naturally occurring cosmic-ray particles to identify areas of lower density inside massive structures.
That discovery is entirely separate from the retracted Biondi and Malanga paper.
This distinction is crucial because the existence of one independently detected cavity inside the Great Pyramid does not validate unrelated claims about enormous underground structures beneath Giza.
Are there really huge structures 2,100 feet below Khafre?
There is currently no independently established archaeological evidence supporting the extraordinary structures described in the researchers’ later claims.
The retracted paper concerned the Great Pyramid rather than serving as independent proof of the much larger Khafre “underground city” claims.
Those claims would require confirmation through other scientific methods, such as ground-penetrating surveys, seismic imaging or archaeological investigation.
Until that happens, descriptions of a vast city beneath Khafre remain claims rather than established archaeological discoveries.
Why does the retraction matter?
Scientific journals rarely retract papers simply because a result is surprising.
A retraction signals that the publication itself has been judged unreliable enough that readers should no longer treat its conclusions as part of the scientific record.
In this case, Remote Sensing specifically cited methodological flaws and statistical errors rather than merely saying that later researchers disagreed with the interpretation.
That gives the development particular importance because the pyramid claims received enormous attention online and were repeatedly presented as if a hidden ancient civilization had been discovered.
The retraction makes clear that the underlying evidence does not currently support that conclusion.
What do the researchers say about the retraction?
Biondi has publicly disputed the journal’s decision.
In a statement discussing the retraction, he argued that the paper’s conclusions came from direct inversion of a Doppler tomographic model rather than statistical inference and questioned why the journal had not publicly identified the specific methodological and statistical errors it cited.
The authors have therefore not withdrawn their scientific claims themselves.
That disagreement is now part of the story, but it does not reverse the journal’s formal decision.
The paper remains marked as retracted in the journal’s records.
Could future research still discover something beneath Giza?
Absolutely.
The Giza plateau remains archaeologically fascinating, and modern noninvasive technologies have already revealed features that were not previously known.
Techniques such as muon imaging, electrical resistivity, seismic surveys and other forms of geophysical sensing can help researchers investigate structures without immediately excavating them.
A genuine discovery of a large underground complex would be extraordinary.
But it would need to survive independent testing and preferably confirmation using more than one method.
That is the difference between a provocative signal and an archaeological discovery.
So, is there an underground city beneath the pyramids?
There is currently no reliable evidence establishing the vast underground city described in the sensational claims surrounding the Giza pyramids.
The scientific paper that was used to support part of the argument has now been retracted after Remote Sensing found serious methodological and statistical problems.
That does not make every unexplored space beneath Giza imaginary. It simply means those spaces still need to be discovered and verified through credible archaeological and scientific methods.
For now, the “underground city” remains a claim, not a confirmed discovery.
And the retraction is a reminder of one of science’s most useful habits: extraordinary pictures and extraordinary stories still have to survive extraordinary scrutiny.
