Search co-ordinators say they have discounted an area of the Indian Ocean, where acoustic “pings” were detected, as being MH370’s final resting place.

The missing Malaysia Airlines plane is not in the search zone off the West Australian coast where acoustic “pings” were detected, but authorities remain confident it is in the southern Indian Ocean.

Hours after CNN reported a US Navy official as saying the pings may have come from the main search vessel itself, the Joint Agency Co-ordination Centre confirmed the now-complete Bluefin-21 underwater drone search that was based around the acoustic signals had led to nothing.

“The Australian Transport Safety Bureau (ATSB) 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,” JACC said on Thursday.

Deputy leader Warren Truss said concentrating on the area where the sounds were picked up in early April was “all you can do in circumstances like this – follow the very best leads”.

Mr Truss said searchers were “still very confident” the plane had crashed into the southern ocean and along a line calculated by British company Inmarsat based on the final “handshakes” between the Boeing 777 and satellites.

Relatives of the 239 passengers and crew were recently successful in calling for Inmarsat’s data – which has not been peer reviewed – to be publicly released because they were unconvinced searchers were looking in the right place.

Mr Truss said a new analysis of all existing radar, satellite and aircraft performance data continued and was expected to define a massively expanded search zone up to 800 kilometres long and 70km wide.

That new analysis would be peer reviewed, he said.

Searchers are also ramping up sea-floor mapping, using more vessels in a survey that is expected to take about three months.

The work has already started in a new zone along the same flight path arc identified by Inmarsat, a JACC spokeswoman said.

“A bathymetric survey has already started to map the floor – not in the same area as where the Bluefin was searching – but the area we’ll be moving to,” she told AAP.

That would help determine water depths, enabling selection of scanning technology that will be needed for a fresh underwater search.

A federal government website will soon call for tenders to undertake the search, with a single prime contractor managing the personnel, equipment and vessels.

While the Bluefin-21 was unable to operate effectively at water depths greater than 4.5km, the next drone may be able to reach depths of 6km, the JACC spokeswoman said.

Mr Truss said the fresh underwater search was expected to begin in August and take up to 12 months.

“Hopefully, there’ll be a breakthrough earlier,” he told parliament.

“Unfortunately this is a painstaking effort in a very large ocean.”

Mr Truss said Australia remained committed to the search.

Late last month when the air search for floating debris was called off and searchers said they would start using private contractors for the underwater search, the cost was estimated at $60 million.

MH370 went missing on March 8 about one hour into a night flight from Kuala Lumpur to Beijing.