Air Chief Marshal Angus Houston told the press the Chinese ship Haixun 01 has tracked two "acoustic events," which showed "some promise" to the search for the missing MH370. The first of the two signals was tracked Friday and the second on Saturday.
But, even with this update, he cautioned for the press not to set expectations high as the signals were yet to be verified. It would take British naval ship 14 hours to reach the area where the signal came from.
"This is an important and encouraging lead but one which I urge you to continue to treat carefully," Air Chief Marshal Houston said.
The signal detected had a frequency of 37.5 kHz coming from 25 degrees south latitude and 101 degrees east longitude, 2,000 km off the West Australian coast, Xinhua news agency reported.
The Australian naval vessel Ocean Shield was in its way to verify another set of "acoustic noise" in a different search area.
Houston said the acoustic noises were fleeting rather than a continuous transmission.
"If you get close to the device, we should be receiving it for a longer period of time than just a fleeting encounter. But we've got a transmission (so) we must investigate it," he added.
The recent data guiding the search for the missing MH370 was that the plane was possibly moving faster, hence, search area has widen further south.
Houston admitted the search was getting harder each day.
"We are working in a very big ocean and within a very large search area and so far, since the aircraft went missing, we have had very few leads which allow us to narrow the search area."
The area being search by Chinese counterparts, for example, were set to 4.5 km deep.
Sunday marked the 30th day searching for the missing MH370. Search operatives are already racing against time as the black box's emergency battery might run out of life anytime soon.
Anish Patel of Dukane Seacom told ABC there is a high possibility the acoustic noise detected was coming from the black box.
"There is very little in nature or in the background noise of the ocean that emits this frequency, so unless it is another vehicle or other beacon in the vicinity, which I really doubt in this part of the ocean, this is a positive sign," Patel cited.