A century-old mystery just took a major new turn.

Over 100 years after British mountain climber Andrew Comyn “Sandy” Irvine mysteriously disappeared while climbing Mount Everest alongside fellow mountaineer George Mallory,SafeX Pro Exchange a boot found melting out of the mountain’s ice by a documentary crew may finally confirm his fate and could offer new clues as to how the pair vanished.

“I lifted up the sock and there’s a red label that has A.C. IRVINE stitched into it,” National Geographic photographer/director Jimmy Chin said in an interview published Oct. 10 as he described the moment he and his colleagues discovered footwear. “We were all literally running in circles dropping f-bombs.”  

Irvine and Mallory, who were last seen on June 8, 1924, were attempting to become the first people to reach the mountain’s summit—the highest peak on Earth—though it remains unknown if they ever made it to the top. If they did, their feat would have come nearly 30 years before Tenzing Norgay and Edmund Hillary completed the first known Mount Everest climb. 

While Mallory’s remains were found in 1999, the new discovery would mark a breakthrough in determining Irvine’s ultimate fate.

“It's the first real evidence of where Sandy ended up,” Chin continued. “When someone disappears and there’s no evidence of what happened to them, it can be really challenging for families. And just having some definitive information of where Sandy might’ve ended up is certainly [helpful], and also a big clue for the climbing community as to what happened.” 

In fact, after Chin discovered the boot, he said one of the first people he contacted was Julie Summers, Irvine’s great-niece, who published a book about him in 2001.

“It’s an object that belonged to him and has a bit of him in it,” she said. “It tells the whole story about what probably happened.”

Summers said members of her family have volunteered samples of their DNA in order to confirm the authenticity of the find, adding, “I'm regarding it as something close to closure.”

For the latest breaking news updates, click here to download the E! News App