Watch: Mummified Fetus Found Inside an Intricately Designed Cedar Wood Coffin

For more than a century, the tiny coffin hid a secret about what's really inside it. The British museum has discovered what is believed to be the youngest mummy to be uncovered from ancient Egypt.

According to a statement by the University of Cambridge, the mummified fetus is believed to be between 16 to 18 weeks old. It is the only academically verified specimen to exist in that age. The tiny body has been resting inside the small wooden coffin with its hands over its chest for thousands of years. British School of Archaeology excavated the coffin in Giza in 1907 and came into the collection of the Fitzwilliam Museum in Cambridge, U.K. in the same year, Discovery News reported.

"It is a perfect miniature example of a wooden coffin of the ancient Egyptian Late Period, dating from 664-525 BC. The lid and box are both made from cedar wood," the museum said in a statement. "Although the coffin is deteriorated, it is clear that the wood was carefully carved on a painstakingly small scale and decorated," it added.

Although the coffin has been in the care of the museum, researchers did not pay too much attention to it thinking it contained mummified organs from embalming procedures back in the days. According to CNN, an X-ray imaging was done at the Fitzwilliam Museum, which is the university's antiquities facility, but was inconclusive, the university said.

Then a micro CT scan was done at the Cambridge University's zoology department later showed pictures of a human body. "Five digits on both hands and feet and the long bones of the legs and arms were all clearly visible," the university said. "Although the soft skull and pelvis were found to be collapsed, the categorical consensus was that inside the bundle was a human fetus estimated to be of no more than 18 weeks gestation."

The fetus, whose gender is unknown, is believed to be the result of a miscarriage. But archaeologists are not sure why it was not carried to full-term. This is not the first time fetuses have been discovered. There have also been two mummified fetuses inside different coffins in King Tutankhamun's tomb, but they were much more developed at 25 weeks and 37 weeks of gestation. DNA analysis in 2010 revealed the fetuses can be Tutankhamun's daughters.

The new finding shows "how an unborn child might be viewed in ancient Egyptian society," Julie Dawson, head of conservation at the Fitzwilliam Museum said. "The care taken in the preparation of this burial clearly demonstrates the value placed on life even in the first weeks of its inception," Dawson said.

The miniature coffin is currently on display as part of the exhibition Death on the Nile: Uncovering the Afterlife of ancient Egypt until 22nd May 2016 at the Fitzwilliam Museum Cambridge.