“Today I can report some very encouraging information which has unfolded in the last 24 hours… The pinger locator deployed from the Australian defence vessel Ocean Shield has detected signals consistent with those emitted by aircraft black boxes,” he said.

Verifying the signals could take days.

“We haven’t found the aircraft yet and we need further confirmation,” Houston warned.

The first signal was picked up in the northern part of the current search area and was held for two hours and 20 minutes before being lost.

The ship then turned around and on the return leg detected the signal again for 13 minutes. On that occasion two distinct pinger locators were audible.

“Significantly, this would be consistent with transmissions from both the flight data recorder and the cockpit voice recorder,” said Mr Houston.

Ocean Shield is one of several vessels searching for missing Flight MH370.

The batteries in the black box run out after 30 days. While there is some after life in them, time is running out – the plane went missing on March 8 with 239 people on board.

Image via Getty