CANBERRA, Australia (AP) — The undersea search for the Malaysian airliner that vanished almost two years ago has found a likely 19th century shipwreck deep in the Indian Ocean off the west Australian coast, officials said Wednesday.

A sonar search for the wreckage of Malaysia Airlines Flight 370 found what appeared to be a man-made object on Dec. 19, the Australian Transport Safety Bureau said in a statement.

A follow-up investigation using an underwater drone captured high-resolution sonar images on Jan. 2 that confirmed that the find was a shipwreck, said the bureau, which is running the search for the Boeing 777 which vanished on March 8, 2014.

The Shipwreck Galleries of the Western Australian Museum conducted a preliminary review of the images and advised that the wreck was likely to be a steel or iron ship dating from the turn of the 19th century, the bureau said.

The bureau on Thursday corrected the potential age of the wreck to the middle of the 19th century or later.

"It looks like a large iron or steel sailing ship sitting upright and very intact dating from mid-to-late 19th, possibly early 20th century," museum maritime archaeologist Ross Anderson told the bureau in a statement.

"It appears it is collapsing in classic iron ship fashion with the bow and stern triangles upright and intact and side plating collapsing out to starboard," Anderson added.

Anderson said he was not able identify the name of the ship based on the image or say whether it had three or four masts, which would narrow the possibilities. He estimated it was 80 meters (260 feet) long.

"It is all but impossible to identify ships or their country of manufacture/port of origin without being able to do more detailed artefact studies, as so many have been lost over the years," Anderson said.

"Often the best clue is something like crockery that may have visible the name of the shipping line or similar," he added.

The wreck was found under water 3.7 kilometers (12,100 feet) deep, 2,600 kilometers (1,600 miles) southwest of the Australian port of Fremantle where the three search vessels are based, the bureau said.

The sea hunt similarly found what appeared to be a man-made object in March last year 3.9 kilometers (12,800 feet) deep. But it wasn't until May that a closer look confirmed that it was not plane wreckage but the wreck of a cargo ship built in the mid-to-late 19th century. Hundreds of such ships were lost during voyages across the Indian Ocean. Neither ship is likely to be identified because of the cost of mounting closer examinations.

Flight 370 is thought to have crashed in the Indian Ocean with 239 passengers and crew aboard more than 1,800 kilometers (1,100 miles) southwest of Australia after mysteriously flying off course during a flight from Kuala Lumpur to Beijing.

Searchers have been combing a 120,000-square-kilometer (46,000-square-mile) part of the Indian Ocean since late 2014. A wing flap found in July on the other side of the Indian Ocean when it washed up on Reunion Island is the only debris recovered.

More than 80,000 square kilometers (30,000 square miles) of the seafloor have been scoured so far, and the search is scheduled to be wound up by the middle of the year if nothing else of Flight 370 is found.

This story has been corrected to showwreck could date back to mid 19th century, not 1800