Launched by Egypt's Ministry of Antiquities, a project called Scan Pyramid aims at scanning the largest pyramids of Egypt in order to detect the presence of any unknown internal structures and cavities.
The technique could lead to a better understanding of the pyramids' structure and how they were built.
The project uses a mix of technologies such as infrared thermography, muon radiography, and 3D reconstruction to look at the inside of four pyramids, which are more than 4,500 years old. They include Khufu, or Cheops, Khafre or Chephren at Giza, the Bent pyramid and the Red pyramid at Dahshur.
"This anomaly is really quite impressive and it's just in front of us, at the ground level," Mehdi Tayoubi, founder of the Paris-based Heritage Innovation Preservation Institute involved in the scanning, told Discovery News.
Temperature differences detected between two adjacent stones from limestone of different qualities usually range from 0.1 to 0.5 degrees.
But at the ground level of the Cheops pyramid, on the eastern side, Tayoubi's team detected an area of three blocks that showed a 6-degree temperature gap with neighboring blocks.
All anomalies detected will be subject to further analysis, the researchers said.
"We need now to build models and thermal simulations to test different hypothesis in order to understand what we have found," Tayoubi said.