Malaysia's Defence Minister Hishammuddin Hussein admitted on Thursday night search authorities are no closer to finding the plane than when it disappeared from radar screens over the South China Sea early last Saturday.

"Until we find the debris or some sign of the plane I will never feel we have made progress," he said.

A massive search by ships and planes from 12 countries is being expanded after after authorities admit they are pursuing no leads.

"The plane vanished into thin air," Mr Hishammuddin said.

The unverified US article in the Wall Street Journal, citing unnamed sources, came as Malaysian authorities discounted the possibility that Chinese satellite images of debris in the Gulf of Thailand were remnants of the plane.

He said China has told Malaysia the image was released by mistake.

The developments are the latest in the highly confusing aftermath of the disappearance of MH370 and its 239 passengers and crew.

After vanishing from radar less than an hour into its journey from Kuala Lumpur to Beijing, no trace has been found despite a massive search and rescue efforts involving more than 80 vessels and surveillance aircraft from 12 countries.

The Wall Street Journal said while the plane's transponders were inactive once it disappeared, data sent automatically from the plane's Rolls Royce engines indicated it may have continued for four hours. This would have taken it up to 4000 kilometres past its last known location.

Malaysian authorities have revealed they had incomplete and imprecise radar information that an unknown aircraft travelled west across Malaysia in the hour after MH370 disappeared, which . If it was heading west, it could have reached the border of Pakistan.

The background of the pilots, crew and passengers are being scoured by investigators for any links to extremist groups. Malaysia media reported the family of one of the pilots was visited by police.

If the plane did continue for four hours after disappearing, another possible explanation is that a rupture in the aircraft led to cabin decompression, depriving pilots of oxygen and leaving them disorientated, unconscious and then dead. In this scenario, the plane would have continued on autopilot until it ran out of fuel and crashed.

A US Federal Aviation Administration warning last year said Boeing 777 planes such as MH370 should be checked for cracking near its satellite antenna. But Malaysia's Ministry of Transport said all airworthiness checks had been done on MH370 prior to its flight. Boeing insists that MH370 did not have the antenna in question.