The mysterious death of several archaeologists who discovered the tomb of Pharaoh Tutankhamun in Egypt in 1922 has puzzled archaeologists for more than a century, with many attributing the deaths to the "Pharaoh's Curse".
But scientist Ross Fellowes claims to have discovered the cause of the "Pharaoh's Curse" which is believed to have killed more than 20 people who opened the tomb of Pharaoh Tutankhamun.

An ancient Egyptian text threatened anyone who tampered with the king's mummified remains with "death from a disease no physician can diagnose".
Author Ross Fellowes claims there was a biological reason behind the deaths.
The study concluded that the cause was radiation poisoning from natural elements containing uranium and toxic waste that had been deliberately placed inside the sealed sarcophagus.
Exposure to the substances could have led to some types of cancer, such as the one that claimed the life of archaeologist Howard Carter – the first person to enter Tutankhamun's tomb 100 years ago.

The theory basically proves that the tomb was indeed "cursed" – in a purposeful biological way – and not in the supernatural way that some ancient Egyptologists claimed.
Carter died in 1939 of a possible heart attack after a long battle with Hodgkin's lymphoma, which affects the body's immune system that fights germs – and radiation poisoning has been linked as a cause of the cancer.
Lord Carnarvon, one of the men who also passed through the precious rooms, died of blood poisoning five months after the discovery.
He suffered a severe mosquito bite, which became infected after being cut with a razor blade.
Shortly after the tomb was opened, there was a brief power outage and all the lights across Cairo went out. Carnarvon's son also reported that his beloved dog yelped and suddenly dropped dead.
Other people involved in the dig died of drowning, stroke, diabetes, heart failure, pneumonia, poisoning, malaria and X-ray exposure. All died in their 50s.
British Egyptologist Arthur Weigall, who attended the opening of Tutankhamun's tomb - where he was accused of promoting the "myth" of the curse - has died of cancer aged 54.

However, inscriptions found inside other tombs throughout Egypt suggest that ancient people knew about toxins. The text included areas that were "forbidden" because of "evil spirits". The study, published in the Journal of Scientific Exploration, explained that high levels of radioactivity were also recorded in Old Kingdom tomb ruins at two sites in Giza and several underground tombs in Saqqara.
The same finish was also found throughout the tomb of Osiris at Giza. Fellowes noted that "intense radioactivity was associated with two stone coffins, particularly from their interior." Other studies have directly measured radon gas at various locations in tombs at Saqqara. Radon gas is an intermediate product of the decay of uranium, with a lifetime of 3.8 days.
Ambient radon concentrations were detected at six locations within the ruins of Saqqarsa: the South Tomb, the diaries of Djoser's pyramid, and the tunnels of the Serapeum tomb.
Thousands of vessels excavated under the Step Pyramid in the 1960s contained up to 200 tonnes of unknown substances that have yet to be identified – suggesting toxins were buried with the mummified remains.