Fresh hopes of finding remains of missing flight MH370

There is fresh hope of finding the remains of the missing Malaysia Airlines flight, as the search zone for flight MH370 has narrowed down to 1,300 sq km, after more audio signals consistent with the plane's black box were detected from the depths of the Indian Ocean today.

An Australian ship searching for the plane has relocated underwater signals, raising hopes that the jet's final resting place will be discovered in "a matter of days", according to one of the chief coordinators of the multilateral hunt.

Angus Houston, the head of a joint agency co-ordinating the search for the missing Boeing 777 in the southern Indian Ocean, said the Australian Navy's Ocean Shield picked up the two signals in a sweep on Tuesday.

Signals had first been discovered over the weekend before being lost, leading to some pessimism as the batteries of the flight recorders will soon run out.

The furthest distance between the four most recent pings is about 25 km, a dramatic narrowing of the focus zone from the 305,000 sq km that the search started with.

"Considering what we started from, which was a huge chunk of the Indian Ocean, it's certainly a remarkable reduction," US Navy Captain Mark Matthews, one of the search coordinators, said today.

Search co-ordinator and former defence force chief Angus Houston said a signal was picked up by Australian vessel Ocean Shield on Tuesday afternoon and was held for five minutes and 32 seconds.

A second signal, detected by the same ship almost six hours later, was held for about seven minutes.

Retired air chief marshal Houston described them as "great" and "encouraging" leads.

"I believe we are searching in the right area, but we need to visually identify aircraft wreckage before we can confirm with certainty that this is the final resting place of MH370," he said, but added: "I'm not going to confirm anything until someone lays eyes on the wreckage."

The signals came three days after Ocean Shield picked up a signal that held for some two hours and 20 minutes, and another that held for about 13 minutes.

It is 33 days since the plane went missing en route from Kuala Lumpur to Beijing - three days beyond the battery's life - but they are known to last several days longer.