THE mystery of missing Malaysia Airlines Flight MH370 has deepened further after investigators said the plane dropped as low as 5000 feet to evade radar in at least three countries.

Whoever was flying the plane is believed to have using a dangerous technique known as terrain masking to ensure that the Boeing 777 and the 239 people on board were not detected by conventional radar.

Australia’s hopes of helping to solve the mystery have been dashed because the nation’s most powerful radar was not looking west towards the Indian Ocean at the time when the missing plane may have passed by Australia.

… Speculation that one of the plane’s pilots, rather than terrorists, may have stolen and then crashed the plane was further heightened after terror expert Rohan Gunaratna debunked British media reports that there was a terror plot to hijack an aircraft using a shoe bomb to blow open the cockpit door.

Mr Gunaratna told The Australian that the reported plot was a decade old and the shoe bomb was intercepted by US authorities in 2004 before it could be used in a plane.

“The only group that has expertise and experience in this domain is al-Qaida,” he said.

“But there is no evidence at this point that it is terrorism. The options are either terrorism, crime or a psychologically affected person.”

Mr Gunaratna said there was no intelligence in the lead-up to the plane’s disappearance to suggest a terror attack was imminent. Foreign Minister Julie Bishop told parliament yesterday any information gathered by Australia’s intelligence services was being passed on to Malaysia.