Search teams scouring the Indian Ocean for the wreckage of Malaysia Airlines Flight 370, which went missing in March 2014, have found a mysterious shipwreck 4km below the sea surface, but still no trace of the aircraft.
The wreckage was detected during a sonar survey carried out from aboard one of the search vessels covering the area off the coast of western Australia where MH370 is believed to have come down.
The sonars detected a cluster of debris, which was further explored by unmanned submarines. Photographs taken by the submarines confirmed the presence of a large number of man-made objects, the largest of which was about 6m long, although it was ruled out that these objects came from an aircraft.
"It's a fascinating find, but it's not what we're looking for,” said Peter Foley of the Australian Transport Safety Bureau (ATSB), which is coordinating the search operations. “We're not pausing in the search for MH370. In fact, the vessels have already moved on to continue the mission."
The discovered wreckage is believed to be that of a mid-19th century merchant ship. Marine archaeologists are examining the photos, which include an image of an anchor and what appear to be lumps of coal to see whether they can identify the ship.
"We've got quite a lot of stories about ships that sank in the Indian Ocean mid-voyage and you would be struggling to tell which is which unless you had a complete catalogue of all the ones lost," said Michael McCarthy, a senior maritime archaeologist at West Australian Maritime Museum.
He added that there may have been hundreds of such ships that had capsized in the ocean during the 19th century and that it has been expected that the teams searching for MH370 may stumble upon some of them.
However, determining the exact story of the mysterious wreckage might be too complicated.
"Being a fairly common type of cargo ship from the 19th century with no obvious cargo remains there, I doubt that anyone would pay the enormous cost of going down to look at it," said McCarthy.
Last month, officials announced they would expand the search area for Flight 370 by another 23,000 square miles in the Indian Ocean if the plane is not found by the end of May.
Crews have covered 75 per cent of the original search area and have moved into the southern portion of the expanded search zone to take advantage of the last decent weather before winter sets in.
Malaysia Airlines Flight 370 disappeared on 8 March 2014 after veering off its scheduled route from Kuala Lumpur to Beijing for reasons unknown. Satellite data later revealed the plane must have remained airborne for about eight hours after its last communication with the ground control and had likely crashed into the Indian Ocean after running out of fuel. There were 239 people aboard the aircraft, a Boeing 777-200ER. All personnel aboard are presumed to have died in the crash.