X-Rays, CAT scans and DNA tests conducted on the male and female mummies over the weekend had predictably revealed the absence of most of their internal organs, researchers said.

According to old Egyptian belief, the hearts were usually left inside the dead body after mummification because they were needed in the after-life. ``To ancient Egyptians the heart was the seat of intelligence and wealth'', said Michael O'Donoghue, a research associate at the South Australian Museum, where the mummies are now kept.

The stomach, intestines, lungs and liver were traditionally removed and separately mummified and either put in packages back into the mummy cavity or into jars, according to O'Donoghue.``But in this case all the organs, including the heart, appear to have been removed,'' he said.

Researchers had hoped testsconducted would reveal some 2,000-year-old secrets and not throw up a mystery of their own. O'Donoghue said that while such a discovery might not be unique, it was certainly unusual.

The fact that both the mummies, which came from different areas had been treated in the same way, removed the likelihood of it being a one-off mistake.

O'Donoghue said a possible explanation might be a general deterioration in mummification techniques of the period involved, which was relatively late in the history of ancient Egypt. Researchers have estimated the male mummy to be about 2,000 years old while the female mummy is thought to be 2,500 years old.

The X-rays revealed the female mummy, Renpit Nefert, was about 40 years old when she died and not about 20 as was initially presumed. They also showed that she probably had a number of children. The male Nubian mummy was thought to be aged at about 30 when he died and had broken two ribs several years before.

There were no signs of trauma, suggesting both died ofdisease. The lack of muscle tissue on Renpit Nefert pointed at a long-standing medical condition that contributed to the wasting of the muscles.

Scientists now hope to learn more about the pair over the next few weeks when DNA sampling and Carbon-14 dating tests are completed.