London, May 25 : British explorer Sir Ranulph Fiennes failed in his second attempt to reach the summit of Everest after succumbing to exhaustion.
The climb was the adventurer's second unsuccessful attempt at scaling the mountain - he suffered a heart attack just 300m from the top in 2005, reports the Telegraph.
At 12.45am local time the Base Camp radio cracked into life with the news that Sir Ranulph was back at the South Col, having turned back due to extreme exhaustion.
Sir Ranulph, who had a triple heart bypass operation in 2003 and is currently in remission for prostate cancer, then radioed down to base camp to ask permission to return all the way down to Base Camp, where he is expected to arrive this afternoon.
The 64-year-old's summit bid began at 7am on Friday when the team left Camp 3 for Camp 4.
On reaching Camp 4, just after lunch, the team rested for just a few hours before pushing on for the summit at 8.30pm.
Sir Ranulph has now begun his descent back to Base Camp after resting at Camp 4.
The attempt - sponsored by Wesleyan Assurance Society and Thuraya - aims to raise 3 million pounds for Marie Curie's Delivering Choice Programme.