The discovery gives scientists a rare opportunity to test for a mummy.
Valid mummies are not normally tested for maintenance, thus reducing the chances of scientific benefit.
The hieroglyphic inscriptions show that the coffin owner is a woman called Mernith et S, and academics believe she was a high priest who lived in 600 BC.
"The hieroglyphic inscriptions indicate that Mir Neith et S was working in the Temple of Sakhmet, the goddess bearing the face of a lion," Fraser said.
"There are keys in hieroglyphics that show us how to mummify the mummy and form the coffin, how the temple of Sakhmat works."