Renowned climber Park Young-Seok and two colleagues last contacted the camp on Tuesday evening while climbing the southern flank of Annapurna, the KAF said. [break]
"They said they stopped climbing at 6,300 metres (20,790 feet) and would descend due to snow and falling rocks, before communication was cut off," it said.
A helicopter and Sherpas sent from Kathmandu searched the area but had so far failed to find them, the KAF said in a statement.
KAF chairman Lee In-Jeong told Yonhap news agency he was not ruling out the possibility that Park may still be alive.
"He had told the camp he was coming back and he should have arrived already," Lee said. "I am worried that he has been in an accident, but it´s also possible that he´s trapped somewhere after losing his communication equipment.
"I am just praying for some good news."
Park, 47, has already scaled Annapurna, one of the world´s 14 highest peaks.
He returned this year to try a different route to the 8,091-metre summit.
In 2005 he became the first in the world to complete the Adventurers´ Grand Slam by conquering all the world´s 14 highest peaks as well as reaching the North and South Pole.
Annapurna is both technically difficult and avalanche-prone and has a much higher death rate among climbers than Everest, the world´s highest peak.
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