Until now, all possible debris have proved to be unconnected to the missing passenger jet.
As the reports emerged last night attention turned again to what might have caused the plane to vanish.
Hishammuddin Hussein, Malaysia’s acting transport minister, said yesterday that MI6 and the CIA are working with Chinese spy agencies in determining what happened to the Boeing 777 and the 239 passengers and crew on-board.
Yesterday Mr Hishammuddin stopped short of plumping for one theory over any other. He said that MH370’s disappearance was due to “terrorism, hijacking, personal and psychological problems, or technical failure”.
“These scenarios have been discussed at length with different intelligence agencies,” he said. “When all the agencies are comfortable in what is able to be released is public, it is for the [Malaysian] chief of police to do that.”
Crash investigators believe the disappearance of the plane – and the decision to disable the communications system – appears to have been a deliberate action but have found no evidence of a motive.
MI6 is understood to have assisted with extensive background checks on each of the 239 passengers and crew aboard the plane but nothing suspicious has emerged.
Mr Hishammuddin said MI6 has also been involved in examining ‘pings’ emitted by the plane which are being used to try to locate its route during the seven hours after its communications systems were disabled.
“Now that we are talking about satellite data and imagery, the CIA has been on board, Chinese intelligence has been on board, MI6 has been on board,” Mr Hishammuddin said.
The Malaysia Airlines flight vanished off radar screens en route from Kuala Lumpur to Beijing more than three weeks ago. Speculation has been rife as to the cause of its disappearance but an explanation has so far proved elusive.
The plane turned wildly off course, its communications systems were ‘deliberately’ disconnected and then it carried on flying south over the Indian Ocean. It is thought to have crashed into the sea off the coast of Australia after running out of fuel.
The suggestion that intelligence agencies are involved will renew speculation its disappearance was a criminal act rather than a mechanical failure.
A fortnight ago the Sunday Telegraph disclosed that an al-Qaeda supergrass had previously warned secret services that four to five Malaysian men had been planning to take control of a plane, using a bomb hidden in a shoe to blow open the cockpit door.
The terror plot was hatched, said the supergrass, in an Afghan terror training camp by the mastermind behind the 9/11 attack on America.
The Malaysian police investigation has centred largely on the actions of MH370’s pilot Zaharie Ahmad Shah, but an examination of a flight simulator seized from his home has uncovered “nothing sinister,” Mr Hishammuddin said.
Zaharie, 53, a father of three and veteran pilot, used the simulator to play three flying games.
The different theories have done nothing to ease the anguish of families. The possibility the plane was seized by jihadi terrorists was raised after it emerged that Saajid Badat, a British-born Muslim from Gloucester, said that he had been instructed at a terrorist training camp in Afghanistan to give a shoe bomb to the Malaysians at the terror camp.
Giving evidence earlier this month at the trial in New York of Sulaiman Abu Ghaith, Osama bin Laden’s son-in-law, Badat said: “I gave one of my shoes to the Malaysians. I think it was to access the cockpit.”
Badat, who spoke via video link and is in hiding in the UK, said the Malaysian plot was masterminded by Khalid Sheikh Mohammed, the principal architect of 9/11.
According to Badat, Mohammed kept a list of the world’s tallest buildings and crossed out New York’s Twin Towers after the September 11, 2001 attacks with hijacked airliners as “a joke to make us laugh”.
Badat told the court that he believed the Malaysians, including the pilot, were “ready to perform an act.”
During the meeting, the possibility was raised that the cockpit door might be locked. Badat told the court: “So I said, ‘How about I give you one of my bombs to open a cockpit door?’ ” The disclosure that Malaysians were plotting a 9/11-style attack raises the prospect that both pilots were overpowered and the plane intended for use as a fuel-filled bomb. One possible target, if the scenario is correct, will have been the Petronas Towers in Kuala Lumpur, a symbol of Malaysia’s modernity and the world’s tallest buildings from 1998 until 2004.
Lawyers in the US acting for the family of a missing passenger, however, believe the disappearance has been caused by some form of mechanical failure.
Both Boeing and Malaysia Airlines are facing legal demands to disclose what they knew of those possible mechanical failings.
“We are working on the theory that it is a design defect,” said Monica Kelly, a US attorney acting on behalf of Januarai Siregar, whose son, Firman, was on the flight.
The “Petition for Discovery”, lodged in the Circuit Court of Cook County, Illinois, is intended to force both Boeing and Malaysia to release all the material they hold on the aircraft.
Until now both Boeing and Malaysia Airlines have steadfastly refused to comment on what may have caused the plane to disappear.
But details of a number of incidents involving other Boeing 777s have emerged, including a cockpit fire at Cairo Airport in July 2011.
Although passengers and crew were evacuated safely, investigators found that the blaze was caused by a short circuit igniting an oxygen pipe.
Regulators in America and Europe issued a directive ordering the replacement of the oxygen pipes with a replacement less likely to conduct electricity. The work is estimated to cost about £1,500 to put right but last week Malaysia Airlines refused to say if the specific work had been done.
A spokesman said: “All mandatory orders issued by aviation authorities relating to aircraft in our fleet have been complied with by Malaysia Airlines.”
In the court petition, Mr Firman’s lawyers, have demanded details of who designed and manufactured the oxygen system. It has also demanded Boeing release documents showing who had information “of the evidence of findings of corrosion and fractures in the fuselage of the subject aircraft and other 277-200ER aircraft that could lead to catastrophic fatal depressurisation of the cockpit.”
The petition has also demanded Boeing provides details of who was responsible for servicing the plane and who last inspected the fuselage and communications system.
Malaysia Airlines in turn is facing a demand to provide details of who was responsible for training and carrying out psychological evaluations of the crew.
The airline is also facing a demand to provide information about previous aircraft damage incidents and who was responsible for training crew in the event of a cockpit fire or depressurisation.
Yesterday a Chinese surveillance plane yesterday spotted three objects – coloured white, red and orange – in a new search zone west of Perth and an Australian P3 Orion spotted numerous items. Though the colours of the objects appeared to match Malaysia Airlines’ colours, the source of the objects has yet to be identified. Several small objects spotted by planes on Friday were yesterday picked up by Australian and Chinese ships and were found to be unrelated to the plane.
Eight aircraft and four ships conducted searches across 97,000 square miles yesterday, with another five ships due to join the search today.
Air Vice-Marshal Kevin Short, the head of New Zealand’s military, said authorities expected parts of the plane to be floating, including fuel tanks, composite materials and plastics.
Authorities have abandoned a search area in which they had scoured for days for objects spotted by five satellites and instead moved to an entirely new zone about 700 miles to the north. The new zone, spanning about 123,000 square miles, is in calmer waters and closer to shore, allowing aircraft to spend more time flying overhead.
But the area is still 1,150 miles from Perth and was described by Australian prime minister Tony Abbott as inhospitable, inaccessible and “extraordinarily remote”.
“We are trying to find small bits of wreckage in a vast ocean and while we are throwing everything we have at it, the task goes on,” he said.
Mr Hishammuddin met with Malaysian families of passengers and crew aboard the plane and indicated that he has not given up hope of finding “possible survivors”. Malaysia’s government and Malaysia Airlines last Monday declared that the plane had crashed in the southern Indian Ocean and that no passengers survived, though no wreckage has yet been found.
“Miracles do happen, remote or otherwise,” Mr Hishammuddin said.
“I cannot give them [relatives] false hope … No matter how remote the odds, we will pray, hope against hope, and continue to search for possible survivors.”
Families of some of the 153 Chinese passengers aboard the plane are planning to travel to Malaysia to confront authorities. Some Chinese family members have accused Malaysian authorities of hiding information about the flight and bungling the search.
Steve Wang, a representative of some of the families, said Malaysian authorities “have not been able to answer all our questions”.
“It’s either they are not in charge of a certain aspect of work or that it’s still being investigated, or it’s not convenient for them to comment,” he said.