Australian Prime Minister Tony Abbott said on Friday he was “confident” that the latest signals picked up by search vessels were from the black box on board missing Malaysia Airlines flight 370.

Speaking to reporters after arriving in Shanghai on an official visit, Mr. Abbott said the search area had been narrowed down, indicating that vessels were close to a breakthrough after more than a month of searching for the Boeing 777, which disappeared around one hour after taking off from Kuala Lumpur in the early hours of March 8. Bound for Beijing, the plane had 239 people on board, including five Indians, 154 Chinese, and 38 Malaysian nationals.

“We have very much narrowed down the search area and we are very confident that the signals that we are detecting are from the black box on MH370,” the Australian Prime Minister told reporters in Shanghai, according to Reuters.

Recovering the black box, which records flight data, is crucial to discovering what went tragically wrong on board MH370, which disappeared from air traffic radars somewhere over the Gulf of Thailand.

Malaysian officials said investigations had led them to believe that on-board transmitters had been manually disconnected and the plane had been “deliberately” diverted wide off-course, before tracking far south to the Indian Ocean off the coast of Australia and plunging into some of the world's most remote waters.

Rescuers are facing a race against time to recover the black box, which may be several thousand feet under water, on the ocean bed. As batteries in the black box, which is also equipped with underwater beacons, usually last for around 30 days, rescuers are already on borrowed time, experts said.

Mr. Abbott's comments on Friday are only the latest in a long-winding search effort that has already seen many false leads. The twists and turns have brought anguish to relatives, who have been through an unimaginably traumatic few weeks in waiting for news of their loved ones.

Here in Beijing, many relatives of the 154 Chinese nationals, who still wait at a hotel for news, have held on to hope - hope which has been fast-diminishing, but would not be extinguished, they said, until there was some concrete evidence about the fate of the aircraft, whether through the recovery of the black box or debris.

With more than 100 aircraft and vessels at one point scouring the waters of the Indian Ocean in recent weeks, the narrowing of the search area to a smaller 600 square kilometre has led to suggestions that a breakthrough may finally be at hand.

Greg Waldron, an aviation expert at Flight Global, said the latest “pings” detected were consistent with that from flight recorders. “The news seems to be very positive,” he told China's State broadcaster CCTV on Friday, speaking shortly after Mr. Abbott's comments. “This is probably the best lead we have had in the search for quite a while”.

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