An elongated skull "held together by metal" could be proof that advanced surgery was performed 2,000 years ago.

Skull

Skull

The piece, which is currently in the possession of the Museum of Osteology in the US state of Oklahoma, is believed to have been damaged during a battle in Peru thousands of years ago.

After returning from a battle wounded, a warrior needed to have surgery on his skull and it is believed that Peruvian surgeons miraculously managed to fuse metal in the damaged area and saved the warrior's life.

Experts at the museum believe the man survived the surgical procedure but there is still lots of unsolved history surrounding the skull.

A spokesperson for the museum told the Daily Star newspaper: "We don’t know the metal. Traditionally, silver and gold were used for this type of procedure.

"We don’t have a ton of background on this piece, but we do know he survived the procedure. Based on the broken bone surrounding the repair, you can see that it’s tightly fused together. It was a successful surgery."