A group led by filmmaker Jimmy Chin found the boot of Andrew "Sandy" Irvine, the British climber who vanished on Everest alongside George Mallory in 1924. Experts say the mystery involving the duo remains.

Discovery Made by Expedition Team Led by Jimmy Chin During Mount Everest Climb for Upcoming National Geographic Documentary Film, Reported Exclusively

The find comes 25 years after Irvine's climbing partner George Mallory’s frozen body was also discovered on the Himalayan peak.

In his final letter to his wife, Ruth, before he vanished on Mount Everest a century ago, the 37-year-old Mallory, who once famously said he wanted to conquer Everest "because it's there," tried to ease her worries even as he said his chances of reaching the world's highest peak were "50 to 1 against us.