Rescuers have been searching Ben Nevis's North Face. Photo: Graham Lewis

Rescuers have had to suspend the operation to find a missing walker on Ben Nevis because of ‘very challenging’ conditions.

One member of the Lochaber Mountain Rescue Team has already been caught in an avalanche during the search, and the team has lost an expensive drone it was using.

Two walkers were rescued on Sunday but a third man is still missing.

The volunteer rescuers said the search will resume as soon as the weather improves.

A Lochaber MRT spokesperson said: “Conditions on Ben Nevis in the search area continue to be very challenging. At the start of the rescue we had very strong winds and deep snow with considerable avalanche risk.

“One team member had been avalanched earlier in day just above the tree line at Leanachan Forest. The recovery of the two people from the summit was not without considerable risk given the conditions.

“We are grateful to the efforts of R951 [the Inverness Coastguard helicopter crew] who provided excellent support with some exceptional flying in very difficult conditions which allowed us to evacuate the casualties from Half Way Lochan.

“Due to the extreme conditions and darkness we reluctantly were forced to call off search for the third casualty.”

The searches are centred on Observatory Gully, on the mountain’s North Face. Rescuers said Monday’s search was hampered by very high winds and low cloud. A thaw had consolidated snow lower down but conditions higher on the mountain remained challenging, they said.

“A team went into Observatory Gully to assess conditions but there had been many avalanches and a small windslab avalanche low down in the gully, triggered by the team, indicated that the risk continued to be too high to deploy rescuers into the search location.

“Despite conditions being well outside the operational capability of UAVs [drones], it was decided that it was safer to try and search the area using a UAV to see if the images captured could give any clue to location of the missing person.

“Unfortunately the conditions proved to be well outside its operational capability and resulted in the UAV to be lost. Expensive, but better that than the life of a rescuer.”

On Tuesday the Inverness Coastguard helicopter attempted to get to Observatory Gully but conditions were too difficult and the crew had to abandon their efforts.

The Lochaber MRT spokesperson said: “Today the forecast of 90mph winds at sea level and storm-force winds on the mountain with continued high avalanche risk mean that the team have reluctantly decided to delay restarting the search.

“As soon as we get a window in the weather then we will resume.

“Our thoughts are with the family and friends of the missing person and we are sorry we cannot do any more than we have already done.”