French aviation authorities are to open a new investigation into the disappearance of Malaysian Airlines flight MH370, days after a report effectively cleared the pilots of any deliberate act to bring the plane down.

The MH370 Safety Investigation Report that was released on Monday. ( ABC News: Phil Hemingway )

The SR-GTA — the research section of the Gendarmerie of Air Transport — wants to re-examine the satellite data or "pings" that led earlier investigators to conclude the plane crashed somewhere along an imaginary arc in the Indian Ocean, after veering off-course on a flight from Kuala Lumpur to Beijing in March 2014.

The French authority said the presence of four French citizens on board allowed it to carry out its own inquiry, according to a report in Le Parisien newspaper.

The French decision comes a week after Malaysian investigators released their latest report into the plane's disappearance in March 2014, which found there was no evidence to implicate the two pilots in a deliberate act to bring the plane down.

Instead it raised the possibility of unlawful "intervention by a third party", but failed to say who such a third party could be.

Photo showing what was originally thought to be possible debris from the missing Malaysia Airlines flight MH370 floating in the South China Sea, March 12, 2014. Several satellite photos were released on the website of a Chinese state oceanic agency, but were released "by mistake and did not show any debris". ( www.sastind.gov.cn/ )

The French report said the SR-GTA wants to verify the accuracy or authenticity of the satellite "pings" and all original technical data provided by the British satellite communications company Inmarsat, reported Le Parisien.

It was Inmarsat that used communications between the plane and its satellite over several hours on the morning of 8 March 2014 to try to determine a possible crash site.

An Inmarsat spokesperson gave a statement to ABC news on Thursday:

"I can confirm that, via the UK authorities, we have been approached by the French investigation team," the spokesperson said.

We will be supporting their enquiry and are on standby to answer any questions that the French investigation team may have."

In response to specific questions about satellite data the spokesperson told the ABC:

"It is important to stress that the accuracy and analysis of the data conducted by the international investigation team is not being questioned as part of the French investigation."

Families of the 239 people on board have slammed the Malaysian report as a cover-up, hitting out at investigators for not raising the possibility of a murder-suicide plot by one or the other pilot.

Families call for Malaysia to release military radar data

A group known as Voice370 that represents passengers and crew on board MH370 urged Malaysian authorities to hand over all military radar data used to trace the plane's flightpath.

"The Report highlights that the military's primary radar data played a significant role in tracing the aircraft's flightpath," said Voice 370 in a statement.

"Voice 370 calls upon the government of Malaysia to share all available data with independent experts for a thorough peer review and analysis.

"We believe that after 4.5 years since MH370 disappeared, there is no reason to continue to withhold data when its probative value far outweighs any prejudicial effect."

Sorry, this video has expired Victims' families say the MH370 report has no new information

The Le Parisien article condemned the Malaysian report as "imprecise and ambiguous", for "dismissing without any evidence" the possibility of pilot involvement in the plane's disappearance.

It says French investigators want to pursue its inquiries "from scratch" — by seeking the original satellite data from Inmarsat to track the plane's trajectory.

Four French citizens on board MH370 included Laurence Wattrelos, her daughter Amber, 14, and son Hadrien, 17, as well as his French-Chinese girlfriend. They were returning from a spring break in Malaysia.

Graphic of the intended flight path for Malaysia Airlines flight MH370 that last had contact with air traffic controllers on March 8, 2014. ( ABC News )

French media raises depressurisation theories

The article also raises the possibility that the aircraft suffered a major power failure that in turn led to an undetected depressurisation, which slowly depleted the plane's oxygen supply and sent all on board into a coma before it crashed.

It is a theory supported by Xavier Tytelman, a former Army veteran and aeronautical consultant.

"A typical symptom of a slow depressurisation of the aircraft may have gone unnoticed or undetected by the pilots as it may be a secondary problem," he told Le Parisien.

It was a decompression like this that killed 121 people on board a Helios Airways flight in 2005, where a loss of cabin pressure incapacitated the crew and left the plane flying in autopilot mode until it ran out of fuel and crashed.

Similar theories of hypoxia or depressurisation have surfaced in the days since the Malaysian report was released last week.

Author Christine Negroni, who wrote the book The Crash Detectives, believes the plane depressurised at 35,000 feet.

"The first officer, alone in the cockpit, put on his emergency oxygen mask but failed to get 100 per cent oxygen under pressure which would be required to restore his intellectual acuity," Ms Negroni said.

Fariq Abdul Hamid was the co-pilot on the Malaysia Airlines flight MH370 that went missing en route from Kuala Lumpur to Beijing.

"Instead, with the insidious feeling of well-being that characterises hypoxia — or oxygen starvation — the pilot turned the plane back toward Kuala Lumpur. He knew there was a problem but didn't have the brain processing power to act appropriately."

"This explains why he turned in one direction then another before passing out as the plane headed into the world's most remote sea," she said.

Blogger "Baptiste" also supports the theory of depressurisation, and says the earliest investigations suggesting the plane had been picked up flying erratically over the Malaysian mainland were simply wrong.

"The most plausible explanation is that the aircraft simply flew undetected, in a straight line, past Kuala Terengganu or Kuala Lumpur, since everyone onboard was unconscious at this point, eventually running out of fuel further into the Indian Ocean.

"The damage to the Satellite Data Unit and the instrument measuring the BFO making their data misleading, putting the 7th arc, where the aircraft was in its final minutes, in a different location than the investigative team believed, based on this obviously unreliable data."

Airport security camera vision

But other theories too have emerged in the wake of last week's report, including the possibility that two unidentified men seen on airport security cameras sneaked onto the plane before take-off and removed the pilots' oxygen tanks, in order to take control of the plane themselves.

Ken St Aubin, who describes himself as an electrical systems specialist on flight simulators, says the most likely culprits are sophisticated hijackers or stowaways, who gained access to the plane but weren't on the passenger list.

In a blog post he cites the case of two men caught on airport CCTV cameras who allegedly bypassed security, as other passengers checked in for the ill-fated flight. The men were originally shown in a French magazine report.

CCTV security camera still of passengers boarding MH370 as shown in a France 2 documentary and commented upon in blogs. ( France 2 via Ken St Aubin )

One was dressed in an airport ground crew uniform, and the other wore a black shirt. But it is alleged that neither man has ever been identified.

Mr St Aubin hypothesises that either or both men could have walked onto the tarmac posing as maintenance workers, and gained access to the plane via the Electrical/Equipment bay under the fuselage.

Many have called on Malaysia to supply the raw military data that would allow an independent review of its speed, altitude and position.

"Some of the variations in speed and altitude are beyond the capabilities of the plane," says Victor Iannello on his blog Radiant Physics.

"For instance, the measured speed and altitude at 18:01:59 UTC are 589 knots and 58,200 ft. One minute later, the speed and altitude are recorded as 492 knots and 4,800 ft.

"How the military radar data can be so far out of calibration is unexplained."

Mr Iannello says another search for MH370 is unlikely unless a case can be made that there is a reasonable probability of success.

The best chance of that now lies with France's Gendarmerie of Air Transport .