The remains of what is believed to be a 13th century Mongol ship have been discovered by a team of researchers off the coast of southern Japan.

A portion of the keel - 36 feet long - was found buried deep inside the sands off Nagasaki Prefecture on the island of Kyushu. The discovery is regarded as the first time such an old ship has been found in such an intact state. Researchers believe the vessel can be dated to between 1274 and 1281, when Kublai Khan (pictured), emperor of the Yuan Dynasty that ruled China, made failed attempts to conquer Japan.

According to a report in the Telegraph, researchers have previously been able to recover only anchor stones and cannonballs from the scattered wrecks of the Mongol fleets. They believe this find will shed new light on the maritime technology of those days.

The vessel was detected with the help of ultrasonic equipment, while at a depth of approximately 75 feet. The team of archaeologists who have been carrying out the search selected that spot as it has yielded other items from Mongol ships.

It is believed that the discovery will provide vital clues about the cause and nature of the Mongol defeat and will also shed light on shipbuilding skills of the time.