Royal Marine commandos have misplaced an assault rifle during a training exercise in Dartmoor.
The Royal Navy is desperately searching the national park while insisting the missing SA80 automatic rifle is “unloaded”.
Drills in the vast Devon moorland were cut short to initiate the search for the weapon - a standard issue British army rifle which has an effective range of 400 metres.
Military sources said while they were not making excuses the “unloaded” weapon could not be used with immediate effect.
“You’ve got to remember that Dartmoor is difficult terrain,” the source told the Telegraph.
“There are crevices, ditches, all sorts so it isn’t that easy to find it, but they are searching.
“You’ve got to remember these people are tired, it’s dark, wet, miserable, they get distracted. But that’s not an excuse.”
A Royal Navy spokesperson said: “We are investigating an incident related to the loss of an unloaded rifle by the Commando Training Centre Royal Marines. The incident is under investigation, therefore it would be inappropriate to comment further.”
It comes days after the high court overturned a decision to ban wild camping in Dartmoor National Park.
Wild camping, or “backpack camping”, was banned on Dartmoor after hedge fund manager Alexander Darwall bought 1,620 hectares of the park.
Darwall had taken the Dartmoor National Park Authority (DPA) to court, saying that the right to wild camp had never existed.
