British scientists have able to confirm that a pair of Egyptian mummies who were thought to be brothers, were in fact half-siblings. According to research published in the Journal of Archaeological Science, the 4000-year-old mummies had the same mother but different fathers.

Named the "Two Brothers", the mummies belonged to high-ranking men named Khnum-nakht and Nakht-ankh from ancient Egypt's 12 Dynasty period. Science Daily reports that their tombs were first discovered by Egyptologists Flinders Petrie and Ernest Mackay in 1097 at Deir Rifeh, a village 250 miles south of Cairo. Based on the hieroglyphic inscriptions on the coffins, they were identified as the sons of an unnamed local governor. The name of their mother was Khnum-aa.

Dating the linen wrappings used in the mummification process suggests that Khnum-Nakht died at the age of 40. His half-brother Nakht-Ankh died a few months later. He was around 60 years old at the time.

"Although their coffin inscriptions indicate that Nakht-Ankh and Khnum-Nakht were brothers, when the mummies were unwrapped in 1908 the skeletal morphologies were found to be quite different, suggesting an absence of family relationship," the new research paper states.

When first unwrapped, Egyptologist, Dr Margaret Murray and her team noticed the differences in the two mummified bodies. At the time, they suspected that one of the men was adopted.

Two brothers mummies
The tombs of the Two Brothers were first discovered in 1907 Manchester Museum, The University of Manchester

After extracting samples from the teeth of the two mummies, scientists were able to use a next generation method of DNA sequencing to identify differences in their Y chromosomes.

"It was a long and exhausting journey to the results but we are finally here. I am very grateful we were able to add a small but very important piece to the big history puzzle and I am sure the brothers would be very proud of us. These moments are what make us believe in ancient DNA," Dr Konstantina Drosou, of the School of Earth and Environmental Sciences at the University of Manchester who conducted the DNA sequencing, said.

DNA testing had been done in 2014 which suggested that the two men's mitochondrial DNA was not the same and proved that they did not have the same mother. However, the samples, which were taken from the mummies' livers and intestines, were prone to contamination which may have affected the results.

Campbell Price, curator of the Egypt and Sudan collections at the Manchester Museum in England and co-author of the latest paper claims that paternal figures may have been peripheral family members. "Power may have been transferred down the female line rather than simply by a son inheriting [high rank] from his father," Price said.