The Rafale, built by Dassault Aviation, is France's most sophisticated fighter but Paris has not found a foreign buyer for it in eight years, often losing out to rivals offering cheaper, less high-tech models.

The Navy issued pictures showing the jet stopped in grass about 100 metres past the end of a runway at the Lann-Bihoue military base in Brittany.

Its landing gear was intact and there was little obvious damage in the pictures but a tarpaulin had been placed over the nose and cockpit.

"The causes of the event cannot be established for the moment and will have to be determined by a technical investigation," the navy said.

The pilot, who was conscious after the accident, was taken to hospital and kept there for observation, it added.