British researchers using a high powered X-ray machine were successful in revealing secret that was hidden for almost 3,000 years in the sands of the cradle of civilization.

Although the hidden secret has been revealed but it has also stimulated debate over what those secrets mean for their understanding of ancient Egyptians and their religious beliefs.

As part of a BBC documentary scheduled to air on Monday, scientists from the University of Manchester have unveiled CT scans of the insides of more than 800 ancient Egyptian animal mummies.

Egyptologist Dr. Lidija McKnight told The Washington Post that almost a third of the animal mummies examined were completely empty and another third contained only partial skeleton bones.

"That is the most shocking to most people, that some of them don't contain what you are expecting. I think the more we look at them, the more that becomes sort of commonplace", said Dr. McKnight.

She further said that many of the mummies, which dated between 1000 B. C. and 400 A. D., looked similar on the outside but contained very different things inside.

For instance she said two cat mummies might look same but one of them would contain a complete kitty skeleton, and the other would be empty.

Furthermore explaining she said the mystery of the empty mummies were first surfaced decades ago. She said when these mummies were discovered for the first time the archaeologists unwrapped some of them just to see what was in there, they were quite surprised to see that they weren't complete animals.

Some reports and recordings from those times suggest that they were fake mummies. But McKnight told The Washington Post she believes that there is something more to what they are looking at.

As per current estimates the Egyptians left behind more than 70 million animal mummies. Many people mistakenly think that all Egyptian mummies were pets sacrificed to accompany their owners into the afterlife, McKnight said.