KATHMANDU, Nepal — An octogenarian Nepalese mountaineer who was on a mission to reclaim his title as the oldest climber on Mount Everest died on Saturday afternoon at base camp, government officials said.

The climber, Min Bahadur Sherchan, 85, died at 5:14 p.m., said Dinesh Bhattarai, the director general of the Nepal Department of Tourism.

The cause of Mr. Sherchan’s death was not immediately clear, but Gyanendra Shrestha, a government mountaineering official at the Everest base camp, said it might have been a heart attack.

Tilak Ram Pandey, a government liaison officer for Mr. Sherchan’s team who was near the base camp, said Mr. Sherchan’s body would be taken to Kathmandu for an autopsy on Sunday.