Key members of the Independent Group of international aviation and data experts who advised Australian authorities in the hunt for MH370 say crucial data that could help find the plane is being withheld.

The underwater search for the Malaysia Airlines jet officially ended on Tuesday without finding any trace of the Boeing 777 in the designated area - a 120,000sq km section of previously uncharted sea bed in the southern Indian Ocean off Perth known as the "seventh arc".

But if you assumed those tasked with finding this needle in a haystack had been given every piece of information available to solve what is now regarded as the greatest aviation mystery in history, you would be wrong.

News.com.au reports that Malaysia withheld, and continues to withhold, from the Australian Transport Safety Bureau (ATSB) and consulting experts, vital radar data containing possible clues to the location of the Boeing 777 - or what is left of it.

Advertisement

It can also be revealed shocking examples of negligence and obfuscation displayed by Malaysian authorities in the hours after the plane vanished en route from Kuala Lumpur to Malaysia on March 8, 2014, with 239 passengers and crew on board.

At least 20 pieces of wreckage, including at least one cabin fragment - confirmed as having come from the plane - have washed up on islands in the Indian Ocean off the coast of Africa over the past two years.

One promising piece was found by relatives of MH370 passengers who were so frustrated at the lack of progress that they flew to Madagascar and sifted through the sand banks with their own hands.

However, the black box believed to hold the secrets of MH370's final hours has never been found.

On Wednesday, Australian Transport Minister Darren Chester revealed the paradoxical criteria that needed to be met before the government would consider resuming the underwater search.

"We need to have credible new evidence leading to a specific location before we would be reasonably considering future search efforts," he said.

In other words, the government needs to know exactly where the plane is before it will resume the search for it.

DEFENCE SURVEILLANCE DATA FROM FOUR NATIONS MISSING

HMAS Success scans the southern Indian Ocean. Photo / AP
HMAS Success scans the southern Indian Ocean. Photo / AP

News.com.au approached MH370 investigators Victor Iannello (US) and Don Thompson (UK), who have been members of the Independent Group since its inception, to ask if they believed they had been denied access to data that could more accurately pinpoint the plane's location.

The answer was yes and plenty of it.

Their shocking revelations about the volume of information withheld by Malaysia and military agencies will have you asking yourself whether the biggest, most expensive search in history was effectively sabotaged.

Thompson told news.com.au his main concern was that crucial radar captured by eight military sites across four nations was never shared.

"My own 'hot button' is that military long-range air defence surveillance data from assets operated at seven, possibly even eight, sites across four nations is absent from the data set available to ATSB," Thompson told news.com.au.

Those satellites, all within range of the flight path MH370 is believed to have taken, are located at Lhokseumawe, Sabang/Pulau We and Sibolga in Indonesia; Car Nicobar and Port Blair in the Indian Andaman Islands; Khok Muang and Phuket in Thailand; and Western Hill, Penang, Malaysia.

Any one of them, or all collectively, could provide the vital clues to the plane's whereabouts.

After forking out about $60 million of an estimated $200 million spent looking for MH370, the Australian public - and certainly relatives of those on board - surely have the right to demand the release of information that could help pinpoint the plane's location and reignite the search.

BIZARRE DISCREPANCIES IN RADAR CAPTURES

Australian Transport Safety Bureau staff examine a piece of aircraft debris at their laboratory. Photo / AP
Australian Transport Safety Bureau staff examine a piece of aircraft debris at their laboratory. Photo / AP

One of the most troubling inconsistencies is some evidence relating to the flight path - shown to victims' families just two weeks after the plane disappeared - was never made available to official investigators.

On March 21, 2014 - when global concern about the missing plane was at its peak - Malaysian air operations chief Lt Gen Ackbal bin Haji Abdul Samad shared specific radar data relating to the purported flight path with victims' relatives in Beijing, Dr Iannello said.

Relatives were shown radar captures placing MH370 in the Malacca Strait between 2.02am and 2.22am Malaysian local time, according to Dr Iannello.

Yet for whatever reason, these captures were never shared with the ATSB, he said.

In another discrepancy, evidence of radar coverage placing MH370 in the Andaman Sea at 3.12am - which was later acknowledged to be from Singapore radar - was included in the ATSB report released in June 2014.

Yet this vitally important data was omitted from Malaysia's Factual Information report released in March 2015.

TELEPHONE RECORDS AND CAPTAIN'S FLIGHT SIMULATOR DATA

A waiter walks past a mural of flight MH370 in Shah Alam outside Kuala Lumpur. Photo / AP
A waiter walks past a mural of flight MH370 in Shah Alam outside Kuala Lumpur. Photo / AP

A full copy of the MH370 data communications log has never been made public. The version released has been heavily edited by authorities.

The existence of telephone records indicating First Officer Fariq Abdul Hamid's mobile phone connected to a tower on Penang Island were initially denied by Malaysia.

Authorities later agreed the event had occurred and included details in a secret Royal Malaysia Police (RMP)* report completed in May 2014. Yet this seemingly crucial part of the MH370 timeline was omitted from the Factual Information report released on March 2015.

Details of this midair call have never been made public.

Similarly, WeChat activity detected on Captain Zaharie Shah's mobile phone while MH370 was lined up on the runway just one minute before takeoff, was included without further explanation in the RMP report. There is no mention of it at all in the Factual Information report released a year later.

Another sticking point for Dr Iannello is the confusion over data recovered from Captain Zaharie Shah's home flight simulator.

He said flight paths with points in the Andaman Sea and the Southern Indian Ocean were found on the simulator. Those details, included in the 2014 RMP report, were inexplicably left out of the Factual Information report published a year later.

Dr Iannello said details about how the data was extracted and analysed was never explained by Malaysian authorities.

MALAYSIA'S LACKLUSTRE RESPONSE

A new 25,000sq km area north of the designated search area on the 'seventh arc' has been identified as likely to contain MH370 but will not be explored in the absence of 'credible evidence'. Photo / Supplied
A new 25,000sq km area north of the designated search area on the 'seventh arc' has been identified as likely to contain MH370 but will not be explored in the absence of 'credible evidence'. Photo / Supplied

Malaysia's behaviour over the past three years has been questionable, from its response in the immediate aftermath of the plane's disappearance to the way it has dragged its feet over the collection of suspected debris found off Africa.

Aspects of the nation's response that continue to bother investigators include:

• After MH370 fell off the radar, Malaysia made only two attempts to reach it using SATCOM Voice - a form of long-range communication used by air traffic controllers. These were logged at 2.40am and 7.14am Malaysian local time.
• MH370 was detected by military radar in real time as it turned back and flew across the Malaysian peninsula, yet there was no reported military intercept.
• Malaysian authorities waited four hours after MH370 vanished from radar before initiating search and rescue efforts.

*A secret Royal Malaysia Police (RMP) report related to the investigation of the disappearance of MH370 was completed May 2014. Various French media obtained the complete report in 2016, and major portions of the report are now publicly available.