Malaysia Airlines Flight 370 may have been "purposely" flown around Indonesian airspace on its way to the southern Indian Ocean to avoid radar detection, a government source has claimed.

The Boeing 777, which was carrying 239 people when it vanished on March 8, flew north of Indonesia and around its airspace while making its way to the southern Indian Ocean, a senior official who declined to give his named, said.

Watch: Signals found in jet search

The latest claim about the airliner came as Australian officials coordinating the international search said they were investigating three reports that signals potentially related to the jet's black box had been detected.


On Sunday, an Australian vessel called the Ocean Shield said its underwater "pinger locator" had detected an "acoustic event" that could be linked to the incident.

That followed claims from China that its patrol vessel had detected signals on Friday and Saturday that were identical to those used by the locator beacon of a flight recorder.

Angus Houston, a retired air chief marshal from the Royal Australian Air Force who is leading the international search effort, described Ocean Shield's find as "an important and encouraging lead, but one which I urge you to treat carefully". He said he was "not prepared to speculate on what it might be".

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Tony Abbott, Australia's prime minister, described the hunt for MH370 as "the most difficult search in human history" and urged caution over the reported signals. "We need to be very careful about coming to hard and fast conclusions too soon," he said.

Thomas Altshuler, the vice-president of the company that makes the hand-held "pinger locator" apparently being used by the crew of the Chinese patrol vessel cast doubt on whether such a device would be able to detect a signal coming from so far beneath the ocean. "It is possible to detect something at that depth with a hand-held device, but I don't know how probable," Mr Altshuler, from Teledyne Marine Systems, said.

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The British survey ship HMS Echo, which is also using a pinger locator, is making its way to the area where the Chinese ship made its discovery.

It is now one of 13 ships and 12 planes covering three search areas located about 2000 kilometres north-west of Perth.

Photo / AP

Mr Houston admitted that search teams were running out of time. "This is day 30 of the search and the advertised time for the life of the batteries is 30 days."