Researchers were able to "peel off" the facemask and bandages and discover details about his appearance and the lavish jewellery he was buried with.

They said it was a "unique opportunity" to study how he had originally been mummified and also "how he had been treated and reburied twice, centuries after his death".

There has previously been a reluctance to uncover the ancient ruler's body because of its wrapping decorated with flower garlands and the life-like facemask inset with colourful stones.

The study was carried out with the use of three-dimensional computer topography scanning technology.

Egyptologists knew from decoded hieroglyphics that the mummy had been unwrapped once in the 11th century BC - more than four centuries after his original mummification and burial.

But the experts believed the priests who restored and reburied him did so to repair damage done by grave robbers and to reuse royal burial equipment for later pharaohs.

A unique opportunity

Dr Sahar Saleem, professor of radiology at the Faculty of Medicine at Cairo University and the radiologist of the Egyptian Mummy Project, and first author of the study - published in Frontiers in Medicine - said their findings debunked those theories.

She said: "This fact that Amenhotep I's mummy had never been unwrapped in modern times gave us a unique opportunity: not just to study how he had originally been mummified and buried, but also how he had been treated and reburied twice, centuries after his death, by High Priests of Amun.

"By digitally unwrapping of the mummy and 'peeling off' its virtual layers - the facemask, the bandages, and the mummy itself - we could study this well-preserved pharaoh in unprecedented detail.

"We show that Amenhotep I was approximately 35 years old when he died. He was approximately 169cm tall, circumcised, and had good teeth.

"Within his wrappings, he wore 30 amulets and a unique golden girdle with gold beads.

"Amenhotep I seems to have physically resembled his father: he had a narrow chin, a small narrow nose, curly hair, and mildly protruding upper teeth."

First discovered in 1881

Amenhotep, whose name means "Amun is satisfied" - in reference to Amun, the ancient Egyptian god of the air - ruled from approximately 1525 to 1504 BC and was first discovered in 1881 at an archaeological site in Deir Al Bahari in southern Egypt.

Amenhotep I oversaw what has been described as a golden age in the civilisation's history and, along with his mother Ahmose-Nefertari, was worshipped as a god after his death.

He was the second pharaoh of Egypt's 18th dynasty after his father Ahmose I, who had expelled the invading Hyksos.

Dr Saleem said: "We couldn't find any wounds or disfigurement due to disease to justify the cause of death, except numerous mutilations post mortem, presumably by grave robbers after his first burial.

"His entrails had been removed by the first mummifiers, but not his brain or heart."