A dagger entombed alongside the mummy of Egyptian pharaoh Tutankhamun was made with iron that came from a meteorite, researchers say.

The weapon was one of a pair of daggers discovered by British archaeologist Howard Carter in 1925 within the burial wrappings of the teenaged king.

The origin of its unrusted iron blade has baffled scientists because such metalwork was rare in ancient Egypt.

Tutankhamun was mummified more than 3,300 years ago.

Italian and Egyptian researchers used "a non-invasive X-ray technique" to confirm the composition of the iron without damaging it, according to a study published inthe journal of Meteoritics and Planetary Science.