The government is disputing a world record for a helicopter landing and taking off from the summit of Mount Everest for the first time.
The controversial flights took place last year and were recognised last week by the Federation Aeronautique Internationale, but the authorities in Kathmandu insist the claims are false.
A French test pilot, Didier Delsalle, says he flew the Ecureuil AS350 B3 to the summit twice last May, both times resting on the mountain for longer than the two minutes required by FAI regulations. On-board cameras are said to have recorded the event.
The summit of Everest is 8,850 metres above sea level. Helicopters cannot normally operate at such altitudes, where the thin air, low temperatures, treacherous thermals and high winds pose particular difficulties.
Mr Delsalle hopes that experience gathered during the flights and advances in technology will offer the chance of helicopter rescue for mountaineers stranded in the 'death zone' of Himalayan mountains, above 7,000 metres.
But the Civil Aviation Authority of Nepal has contacted the FAI and the helicopter's maker, Eurocopter, with evidence they say proves the record is bogus, including a statement from Mr Delsalle that he did not 'land' on the summit.
