Scientists have revealed that drugs and alcohol played a key part in the months and weeks leading up to the children's deaths.

Tests on one of the children, a teenage girl, suggest that she was heavily sedated just before her demise....

The mummified remains were discovered in 1999, entombed in a shrine near the summit of the 6,739m-high Llullaillaco volcano in Argentina.

Three children were buried there: a 13-year-old girl, and a younger boy and girl, thought to be about four or five years old.

Their remains date to about 500 years ago, during the time of the Inca empire, which dominated South America until the Europeans arrived at the end of the 15th Century....