The sarcophagus, found under a mound of earth with furniture from the 14th century, could be the example of "an extremely rare burial practice".
A mysterious leaden sarcophagus has been discovered in the bowels of Paris' Notre Dame cathedral after it was devastated by a fire, and it will soon be opened and its secrets revealed.
The announcement came from French archaeologists on Thursday, just a day before the third anniversary of the inferno that engulfed the 12th century Gothic landmark, leading to a massive reconstruction project.
During preparatory work to rebuild the church's ancient spire last month, workers found the sarcophagus buried 20 metres (65 feet) underground, lying among the brick pipes of a 19th century heating system.
But it is believed to be much older, possibly from the 14th century.
Scientists have already peeked into the well-preserved sarcophagus using an endoscopic camera, revealing the upper part of a skeleton, a pillow of leaves, fabric and as-yet unidentified objects.
The sarcophagus was extracted from the cathedral on Tuesday, France's INRAP national archaeological research institute said during a press conference.
It is currently being held in a secure location and will be sent "very soon" to the Institute of Forensic Medicine in the southwestern city of Toulouse.
An 'extremely rare' practice?
Forensic experts and scientists will then open the sarcophagus and study its contents, to identify the skeleton's gender and former state of health, lead archaeologist Christophe Besnier said.
Noting that it was found under a mound of earth that had furniture from the 14th century, Besnier said "if it turns out that it is in fact a sarcophagus from the Middle Ages, we are dealing with an extremely rare burial practice".
They also hope to determine the social rank of the deceased. Given the place and style of burial, they were presumably among the elite of their time.
However, INRAP head Dominique Garcia emphasised that the body will be examined "in compliance" with French laws regarding human remains.
"A human body is not an archaeological object," he said. "As human remains, the civil code applies and archaeologists will study it as such."
Once they are done studying the sarcophagus, it will be returned "not as an archaeological object but as an anthropological asset," Garcia added.
INRAP said the possibility of "re-internment" in the cathedral was being studied.