A Chinese woman became the first person to reach the summit of Mount Everest this season, officials said Saturday, but the climb was clouded by controversy because she took a helicopter part of the way.

Forty-one-year-old Wang Jing, reached Everest summit late Friday, accompanied by five Nepalese sherpas, tourism ministry official Madhusudhan Burlakoti told AFP.

"Wang is the first climber to scale Mt Everest from Nepal side and they are now on their way back," he said.

But he said that the Nepalese officials had not yet decided whether to log the climb as an official ascent of the 8,848-metre (29,029-foot) mountain because she used a helicopter for a large part of the way.

The ascent comes just over a month after an avalanche killed 16 Nepalese guides in the deadliest ever accident on Mount Everest, spurring a virtual shutdown of the world's tallest peak.

Wang and a US woman climber had decided to fly to Camp 2 on Everest because the route below, normally prepared by sherpas beforehand with ropes and ladders, had not been completed this season.

- Successful summit -

The climbers were thought to be the first back on the mountain since expeditions left in controversy over the April 18 disaster.

"We have not yet made any decisions whether to recognise the ascent by using helicopters," Burlakoti said.

But he added that, "We are positive with the attempt she (Wang) made."

"We are happy to acknowledge that Wang and Sherpas took the risk and made the dangerous attempt this season," Burlakoti said.

Wang flew to Camp 2, an advance base camp at an elevation of 6,400 meters (21,000 ft) where climbers spend time to adjust to the increased altitude.

Earlier, flights were made to Camp 2 to transport equipment or in the event of medical emergencies, not to transport climbers.

"With this successful summit to Mt Everest this season, we hope to see other climbers scale Mt Everest this season," Burlakoti added.

But the window for climbing Everest lasts only until May 25, after which the temperature gets warmer and the mountain more dangerous.

The government has stressed the mountain is still open for business despite the effective closure of the season, normally a key revenue earner for the impoverished country.

Most climbers abandoned plans to ascend Everest from the Nepalese side -- the easiest and most popular route up the world's highest peak -- after the avalanche.

The tourism ministry official said there was yet to be any contact with the US climber, Cleonice Weidlich, 51, who landed at Camp 2 on May 8.

The US mountaineer was heading alone for neighbouring Lhotse peak. Lhotse and Everest share the same route as far as Camp 3.

Nepalese authorities added they were losing hope of finding an Indian woman climber, Chhanda Gayen, and two sherpas missing after being hit Tuesday by an avalanche while climbing on Mount Kanchenjunga, the world's third-highest mountain.

A government statement said rescue efforts to find the three were being hampered by bad weather and altitude.

"Despite continuous rescue efforts for five days, it has been hard to know what has happened to them. The chances of rescuing them alive are slim," the statement emailed to AFP said.