The latest possible lead came as the search for Malaysian AirlinesFlight MH370 entered its third week, with still no confirmed trace found of the Boeing 777 or the 239 people on board.

The new potential sighting was dramatically announced by Malaysia's acting transport minister, Hishammuddin Hussein, after he was handed a note with details during a news conference in Kuala Lumpur, scooping the official announcement fromChina. "Chinese ships have been dispatched to the area," Hishammuddin told reporters.

China said the object was 22 meters long (74ft) and 13 meters (43ft) wide, and spotted around 120 km (75 miles) "south by west" of potential debris reported by Australia off its west coast in the forbidding waters of the southern Indian Ocean. The image was captured by the high-definition Earth observation satellite "Gaofen-1" early on March 18, two days after the Australian satellite picture was taken, China's State Administration of Science, Technology and Industry for National Defense (SASTIND) said on its website.

It could not easily be determined from the blurred images whether the objects were the same, but the Chinese photograph could depict a cluster of smaller objects, a senior military officer from one of the 26 nations involved in the search for the plane said.

The wing of a Boeing 777-200ER is approximately 27 meters long and 14 meters wide at its base, according to estimates derived from publicly available scale drawings. Its fuselage is 63.7 meters long by 6.2 meters wide.

Flight MH370 vanished from civilian radar screens early on March 8, less than an hour after taking off from Kuala Lumpur on a scheduled flight to Beijing. Investigators believe someone on board shut off the plane's communications systems, and partial military radar tracking showed it turning west and re-crossing the Malay Peninsula, apparently under the control of a skilled pilot.

That has led them to focus on hijacking or sabotage, but they have not ruled out technical problems.