AN avalanche expert has criticised the delay in holding an inquiry into the death of three climbers in the Cairngorms two years ago.

Renowned expert Alan Dennis, who was on the scene of the accident within 24 hours, fears lessons may not be learnt from the tragedy until a fatal accident inquiry is held.

Mr Dennis believes the accident could have been avoided and only the public scrutiny of an FAI will fully establish what happened and what could be done in the future to prevent a repeat a similar tragedy.

Three people were engulfed by the avalanche in the Cairngorms in February 2013 and died in hospital after they were dug out by rescuers.

The avalanche began as two groups of six climbers made their way up opposite sides of the Chalamain Gap, a deep, rocky cleft five miles south-east of Aviemore, not far from the Cairngorm ski slopes.

One fatality was from a group which was part of a winter skills course run by the national outdoor training centre Glenmore Lodge. The others were part of a second group of off-duty RAF personnel who were on the side covered in snow and were believed to have triggered the avalanche.

Mr Dennis, whose 'Technical Avalanche Services' is based in British Columbia, was in Chalamain Gap the day after he tragedy.

He has been in touch with the authorities as he is frustrated that no decision has yet been taken whether to hold an FAI.

He said one group was on the heavily snow covered slope and the other was on the adjacent wind scoured bare ground.

"Someone triggered the avalanche that buried three people up to four metres deep. It was a very large avalanche considering the scale of the terrain," he said.

"The technical characteristics of the avalanche conditions were well known but may not have been understood by the two parties. There was a well-developed weak layer in the deeper snowpack. The human factors and decision making around what the groups were doing is not known and confused over time by memory, emotion and who is responsible.

"What is clear is that serious mistakes were made and cannot be learned from without some level of independent scrutiny. One response has been to use avalanche transceivers on a discretionary basis, this sets a dangerous precedent in Scotland and would not have saved the lives of the deeply buried.

A spokesman for the Crown Office and Procurator Fiscal Service said no decision could be taken on an FAI until the Health and Safety Executive (HSE) had completed its investigations, which were still ongoing . He added: "Depending on what was in that report we would possibly give considerations to possible criminal proceedings." Only after criminal proceedings had been concluded or ruled out, would consideration be given to an FAI, he said.

An HSE spokeswoman said: "The time taken to date is not unusual. Investigations into fatalities are complex and require specialist input from a variety of sources which takes time."

Meanwhile a spokesman for the sportscotland's Glenmore Lodge said Chalamain Gap had been a tragic accident. The instructors at Glenmore Lodge were highly skilled and always followed the appropriate routes while continually carrying out a risk assessment.

He said Glenmore Lodge's own internal inquiry had produced some answers.

He said: "Our report has enabled us to establish some conclusions and recommendations, review our processes, and continue to support staff, family members, and students involved in the incident. Through our continual dialogue with mountaineering organisations we have been able to share some of the key observations.

"Our investigations concluded that the slope which avalanched had a group on it unrelated to the Glenmore Lodge party, and that our party was well informed about the avalanche conditions, had good awareness of the weak layer deep within the snowpack, and had a continuous dialogue concerning the evaluation of this risk on their journey into the mountains."

He said a sector-wide survey had been conducted leading to a three year trial of avalanche safety equipment at Glenmore Lodge to help inform the mountaineering community about best practice. "This trial is now in its second year," he said.