The BBC's Andrew Cassell: "The avalanche risk was regarded as medium to high"

But it emerged at a joint news conference that at least two of those killed as they rested 3,500ft up the face of the quarry were experienced climbers, contrary to initial reports.

The climbers who died were from a party of six friends who were only an hour into a two-day winter skills climbing course with an "extremely experienced" local instructor when the avalanche struck.

The parents of Emma Ray, 29, and Paul Hopkins, 28, both from Wilmington in Kent, and Matthew Lewis, 28, from Dartford in Kent spoke of their loss.

The mother of the fourth climber killed - Ian Edwards, 30, also from Kent - was understood to be in Spain.

Emma Ray and Paul Hopkins: Experienced climbers

Emma's father, John Ray, said his daughter, who had been together with Paul Hopkins since they were 15, was an "experienced climber" who had scaled most of the major peaks in the British Isles.

Paul's father Ken Hopkins said his son was similarly accomplished, adding: "I am just concerned that they might have been over-keen on the day, but we are not in a position to know that."

Three people survived the tragedy and were rescued in the early hours of Wednesday morning, despite lying almost completely buried in more than three feet of snow for up to 16 hours.

Matthew Lewis: "A veritable action man"

Steven Newton, 24, of Dartford in Kent and Sarah Finch, 25, of Hartley in Kent, were dug out alive, along with instructor Roger Wild, who ran the Mountaincraft climbing organisation and was also a member of the Lochaber Mountain Rescue team that found them.

All three survivors escaped with hypothermia, sprains and bruises and are recovering at Fort William's Belford Hospital.

Matthew Lewis's mother Daphne, who heard about the tragedy from television news, said: "Our thoughts are with Steve and Sarah - the two who were injured.. because they have been through a dreadful trauma.

"They've got to live with that for the rest of their lives, seeing their friends die."

The six climbers involved in the accident were from a group of 15 who were staying on board a barge, north of Fort William, as part of "a fun-loving holiday" including a New Year's Eve party.

The alarm was raised when Mr Wild failed to return by 2130 GMT on Tueday. The avalanche struck at about 1030 GMT that morning and the survivors were found at 0120 GMT on Wednesday morning.

They were kept alive by air pockets in the hard-packed snow.

Mr Wild was praised for following "good mountain practice" and leaving detailed instructions as to the group's whereabouts.