According to the report, mummies found in the Egyptian tomb are in "good condition" and are more than 2,000 years old.
Twelve children and six animals were among the 50 mummies, while the rest were adult men and women told an archaeologist Rami Rasmi.
Glimpse of the finding
Journalists clambered down a ladder and through an underground chamber beneath the sandy soil of Tunah Al-Gebel, 260 kilometres south of Cairo, to glimpse the recent finds.
Identities of mummies still unknown
The identities of the mummies were still unknown, said Mostafa Waziri, secretary-general of the Supreme Council of Antiquities.
"We have not found names written in hieroglyphics," he said, adding it was obvious from the mummification method that the individuals whose remains were found had to some extent held important or prestigious positions.
'Open clay coffins in crumbling chamber'
Some of the mummies were found wrapped in linen while others were placed in stone coffins or wooden sarcophagi.
The remains were also found laying on the floor or in open clay coffins in the crumbling chamber in Minya governorate.
Ambassadors gather at mummy exhibition
Visitors, including ambassadors from several countries, gathered at the discovery site where 40 of the mummies were exhibited during the announcement ceremony.
Mummification: An ancient Egypt practice
While mummification is mostly associated with ancient Egypt, the practice continued under the kingdom founded by Ptolemy, a successor to Alexander the Great, which lasted from 323 BC to 30 BC.
Presence of mummified pets
Archaeologist Mohamed Ragab said two tombs were discovered nine metres underground and contained more than six rooms.
The presence of mummified pets — mostly dogs — showed how important they were for the dead.
"These animals were so dear to their owners that they buried them...in their tomb," Ragab said.
Researchers use artefacts to determine date
Shards of pottery and pieces of papyrus found at the site helped researchers to determine its date, the head of Egypt's Supreme Council of Antiquities Mostafa Waziri said.
Archaeological finding: A joint mission
The archaeological finding was the first of 2019 and was unearthed through a joint mission with the Research Centre for Archaeological Studies of Minya University.
'Skulls and bones'
Skulls and bones are seen inside a tomb during the presentation of a new discovery at Tuna el-Gebel archaeological site.