Egyptologists say they have identified the 3,000-year-old mummy of Hatshepsut, Egypt's most powerful female ruler.
Egypt's antiquities chief Zahi Hawass made the official announcement at a packed news conference in Cairo.
It is being billed as the biggest archaeological find in Egypt since the 1922 discovery of Tutankhamen's tomb.
Archaeologists hope the mummy, which has lain unrecognised for decades, will yield clues about the mystery of her death and subsequent disappearance.
Mr Hawass has set up a DNA lab near the museum with an international team of scientists to verify the identification.
The study was funded by the US television channel Discovery which is to broadcast a documentary on the subject in July.
An important piece of the evidence is said to be that the mummy has a missing tooth, and the gap matches exactly an existing relic, a preserved tooth engraved with Hatshepsut's name.
Some archaeologists have expressed scepticism about the possibility of using DNA technology to identify the queen.
Hatshepsut's temple is one of Egypt's most visited monuments
"It's a very difficult process to obtain DNA from a mummy," US molecular biologist Scott Woodward was quoted as saying by AP news agency.
"To make a claim as to a relationship, you need other individuals from which you have obtained DNA, to make a comparison between the DNA sequences."
DNA is the molecule that contains genetic information in all organisms and can be used to establish family relationships.
In modern times, Hatshepsut's temple was the location of the 1997 Luxor massacre when Islamic militants gunned down 58 foreign tourists, as well as three Egyptian policemen and a tour guide.
Hatshepsut was an important 18th Dynasty ruler in the 15th Century BC, having usurped her stepson, Thutmosis III.
She was known for dressing like a man and wearing a false beard, and was more powerful than either of her more famous female successors, Nefertiti and Cleopatra.
Hatshepsut's funerary temple is one of the most visited monuments around the pharaonic necropolis of the Valley of the Kings in Upper Egypt.
But after her death, her name was obliterated from the records in what is believed to have been her stepson's revenge.
The mummy was found in Tomb KV60, said to be one of the more perplexing tombs in the Valley of the Kings because it contained two unidentified mummies, both of them women.
The tomb was first discovered by Howard Carter in 1903, but it had been ransacked in antiquity and he resealed it. It was re-opened in 1906 and one mummy was removed and identified as Sit-ra, royal nurse of Hatshepsut.
The mummy now said to be of Hatshepsut herself was left behind and did not see the light again until 1990.
Speculation that it is her was fuelled by the fact the mummy's left arm was bent in a pose thought to mark royal burials and it wore a wooden face-piece (possibly to fit a false beard).