Signals consistent with ‘black box’ flight recorders have been heard by an Australian vessel searching for missing Malaysian Airlines flight MH370.

Air Chief Marshal Angus Houston, who is coordinating the search, said the sounds detected by defence vessel Ocean Shield were the “most promising lead” so far in the search for the missing aircraft.

However, Houston warned: “We have not found the aircraft yet and we need further confirmation.”

The plane disappeared on route from Kuala Lumpur to Beijing on March 8th with 239 people on board.

A pinger locator, towed behind the Australian Defence Vessel Ocean Shield, was deployed in the southern Indian Ocean on April 5th.

Two separate detections occurred, Houston confirmed, with the first heard for two hours and 20 minutes before being lost.

The ship then turned around and the signal was heard again for 13 minutes.

The position of the signals needed to be fixed, ACM Houston explained.

Once that happened, the Ocean Shield can lower the Bluefin 21 underwater autonomous vehicle to try to locate wreckage on the sea floor.

However, time is in short supple with the battery powered signal from the ‘black box’ recorders due to expire within days.