Image caption HMS Investigator, shown in an 1851 illustration, settled on the Arctic seabed intact and upright

Canadian archaeologists have located a British ship abandoned in the Arctic while on a 19th Century rescue mission.

Parks Canada researchers found HMS Investigator in Mercy Bay this week.

Canada's government says the discovery bolsters its claim to sovereignty over the Northwest Passage, which is feared threatened by increased shipping.

The Investigator was abandoned while searching for the Franklin expedition, itself lost with all its crew during a mission to discover the passage.

"It's an incredible sight," Canadian Minister of the Environment Jim Prentice told the BBC by telephone from Mercy Bay.

"You're looking at what people have not seen in 156 years, which is a remarkably intact British sailing vessel."

The Investigator, captained by Robert McClure, left Britain in 1848, ultimately making two attempts to find the Franklin expedition.

Its crew abandoned the ship on the western side of the Canadian Arctic when it became trapped in pack ice.

Running low on supplies and food, Capt Robert McClure and his men were eventually rescued by another party from the Royal Navy.

'Largely intact'

Archaeologists discovered the ship under about 25ft of pristine, icy arctic water this week using sonar and metal detectors.

"You could make out all the planking on the deck, the details on the hull, all of the detail of the timber," Mr Prentice said. "It's sitting perfectly upright on the floor of the ocean."

The Canadian researchers also found three graves of British sailors who died of scurvy on the 1853 expedition.

Parks Canada, a government agency, will inventory and study the ship and other artefacts but will not remove them. It has been in touch with the British government regarding the sailors' remains.

Capt McClure is credited as the first European to discover the western entrance to the Northwest Passage.

Mr Prentice said the discovery of the Investigator supported Canada's historical claim to the region, which the country inherited when it gained independence from Britain.

The issue of sovereignty has become increasingly important to Canada as the melting of arctic ice has increased interest in marine shipping through the Northwest Passage.