PERTH, Australia - An Australian navy ship has detected new underwater signals consistent with aircraft black boxes, the chief of the MH370 search said Monday, calling it the "most promising lead" yet in the month-old hunt for the missing plane.
Retired Australian defence force chief Angus Houston said the acoustics emanating from deep down in the Indian Ocean showed that the multinational search by ships and planes seemed to be "very close to where we need to be".
The apparent breakthrough comes as the clock ticks past the 30-day lifespan of the emergency beacons of the two data recorders from the Malaysia Airlines jet, which vanished March 8 with 239 people on board en route from Kuala Lumpur to Beijing.
"The towed pinger locator deployed from the Australian defence vessel Ocean Shield has detected signals consistent with those emitted from aircraft black boxes," Houston told a press conference.
He said more information is needed but called the findings of the past 24 hours "very encouraging".
'Best information yet'
One signal lasted for two hours and 20 minutes, the second for 13 minutes.
"On this (second) occasion two distinct ping returns were audible," Houston said, adding that was consistent with transmissions from both the flight data recorder and the cockpit voice recorder, which have separate beacons.
"This is a most promising lead and probably in the search so far it's probably the best information that we have had," Houston said.
Malaysian Transport Minister Hishammuddin Hussein told reporters in Kuala Lumpur: "We are cautiously hopeful that there could a positive development in the next few days, if not hours."
The Malaysian government and the state flag-carrier have come under severe criticism for the unprecedented loss of a jumbo jet.
Commander William Marks of the US Seventh Fleet said one of the signals strengthened for a time, then weakened, indicating crews were near its source.
"That is encouraging because that is what you would expect if you are indeed moving toward the black box - that it should get stronger and as you move away from it, it should get weaker," he told AFP.
Malaysian investigations into the aircraft's disappearance have centred on hijacking, sabotage or psychological problems among passengers or crew, but no supporting evidence has turned up.
In the absence of confirmed wreckage, the data recorders or other evidence, relatives of those aboard - most were Chinese - have endured an agonizing wait for information.