A US navy ship has detected signals believed to be coming from the flight recorder of an Indonesian plane that went missing with 102 people aboard on New Year's day, the US embassy in Jakarta said on Thursday.
Wreckage from the missing Adam Air Boeing 737-400 started turning up in waters on the west coast of Sulawesi over recent weeks, but crash investigators want to find the black box and main body of the plane to determine the fate of the doomed plane.
The USNS Mary Sears, an oceanographic survey ship with specialized equipment, had been helping search the waters in the area.
"During the search of the projected crash site of Adam Air Flight 574, the Mary Sears, using a Towed Pinger Locator, detected pingers on the same frequency of the black box associated with the missing airplane," the US embassy said in a statement.
After sweeping the ocean floor around the area, the ship found heavy debris scattered over a wide area and was analyzing the data, it said.
The embassy said the information had been passed onto Indonesian authorities and the ship would leave the area on Friday.
However, the chief of Indonesia's transport safety board said he has not yet received such a report.
The Indonesian head of the search mission said earlier this month that the search for the plane's main body and black box was being hampered by the depth of the sea in areas where metal objects had been detected in the Makassar Strait.
A flight recorder can give off signals for 30 days to aid detection, but this one may be lying in waters as deep as 1,700 metres (5,600 ft) in the area.
The 17-year-old plane was heading from Surabaya in East Java to Manado in northern Sulawesi when it vanished in bad weather. The plane made no distress call, although the pilot had reported concerns over crosswinds.