Australia has already spent approximately $43 million during the first phase of the search for the missing MH370. The air and water search activities had cost Australia almost $1 million daily. This was based on the estimate of Kym Bergmann, editor of Asia-Pacific Defence Reporter and former government defense adviser.

Defense's HMAS Success alone outlaid $500,000 a day in operation while other ships such as HMAS Toowoomba, MV Seahorse Standard, HMAS Perth and Australian Defence Vessel Ocean Shield and several RAAF AP-3C Orion aircraft were also used for the search.

The international authorities, comprising the team searching for the missing plane, currently support the findings that the pings did not come from the MH370 and instead came from a man-made source, Michael Dean, U.S. Navy's deputy director of ocean engineering, told CNN.

"Our best theory at this point is that (the pings were) likely some sound produced by the ship ... or within the electronics of the Towed Pinger Locator. Always your fear any time you put electronic equipment in the water is that if any water gets in and grounds or shorts something out, that you could start producing sound," Dean said.

During the first phase of the search, the Australian ship Ocean Shield towed a U.S. Navy pinger locator to track underwater signals across southern Indian Ocean. The pinger locator towed picked up two acoustic signals, with one ping having a duration of more than two hours, Joint Agency Coordination Centre (JACC) announced. Another two days passed and two more with five and seven minutes in duration of acoustic signals were tracked.

''We are confident that we know the position of the black box flight recorder to be within some kilometers,'' Australian Prime Minister Tony Abbott said at that time.

These pings that Abbott was "confident" were the same pings that Dean spoke about. To put it simply, the pings may have instead been produced by the searchers themselves.

"It could be that just the way the echoes work and the way that the sound bends around in the ocean because of temperature differences and salinity differences, it can make a complete U-turn. It can bend back on itself, and actually, you think you're listening to something, but it acts just like a mirror; you're just listening to yourself," Erik Van Sebille, oceanographer of UNSW told ABC's 7:30 program.

"I am not saying that what Michael Dean said was inaccurate. But what we are saying is that it is not his place to say it. The Navy is continuing to work with our partners to more thoroughly understand the data acquired by the Towed Pinger Locater," U.S. Navy spokesman reacted to Dean's statement with CNN. The spokesmam said Dean's statement was "premature."

"As such, we would defer to the Australians, as the lead in the search effort, to make additional information known at the appropriate time," the spokesman added.

JACC released a statement saying the vicinity of the acoustic signals was now discounted as the final resting place of the missing MH370.

"The Australian Transport Safety Bureau has advised that the search in the vicinity of the acoustic detections can now be considered complete and in its professional judgment, the area can now be discounted as the final resting place of MH370,'' the JACC statement read.

The new phase of the search will now go underwater and could take another year.

"Knowing the sea floor terrain is crucial to enabling the subsequent underwater search. The underwater search will aim to locate the aircraft and any evidence - such as aircraft debris and flight recorders - to assist with the Malaysian investigation of the disappearance of MH370. A single prime contractor will be chosen to bring together and manage the expertise, equipment and vessels to carry out search,'' the JACC said.

"We are still very confident that the resting place of the aircraft is in the Southern Ocean,'' Transport Minister Warren Truss said.

Meanwhile, detailed fact sheets of MH370's next phase of search were released by the Australian Transport Safety Bureau.