A Search and Rescue helicopter was apparently used to drop off servicemen for a round of golf.
Pictures of the yellow Sea King landing at Willingcott Valley Golf Course near Woolacombe, Devon, were published in the Daily Mirror.
A dozen passengers climbed out of the aircraft to play nine holes on Wednesday after flying from a nearby air base, the paper said.
As questions were asked about the appropriate use of military resources, a Ministry of Defence spokesman said: "There are strict rules in place regarding use of military aircraft and we are urgently investigating this incident to ensure regulations have been observed.
"Search and Rescue cover was not compromised in any way while this sortie took place."
The helicopter is thought to have carried mostly non-commissioned officers from RAF Chivenor in north Devon.
Soldiers' lives are being put at risk because of helicopter shortage and search and rescue is under great strain. The public will want answers on how the MoD this is an appropriate use of resources.