The Malaysian government has confirmed that flight MH370 was deliberately interfered with – and with that confirmation, have come new theories about the disappearance of the jet.

Malaysia’s Prime Minister Najib Razak has revealed that investigators have not pinpointed a specific explanation, but have widened the search for the location of the plane to two corridors: the Kazakhstan-Turkmenistan border area, and a swathe from Indonesia to southern India.

“Despite media reports that the plane was hijacked, we are investigating all major possibilities on what caused MH370 to deviate,” the Prime Minister said. While conspiracy theories abound, these are five of the major theories regarding the disappearance of MH370 that authorities are currently investigating.

1. The pilot hijacked Malaysia Airlines MH370.

US intelligence forces believe that the pilot and co-pilot may be responsible.

Prime Minister Najib Razak has revealed that communications were deliberately turned off “by someone on the plane”. The Prime Minister further confirmed that “deliberate actions” were behind the plane’s disappearance.

A US official has told CNN that they believe pilot Captain Zaharie Shah and his co-pilot Fariq Abdul were responsible for the disappearance of the plane.

Police are reportedly investigating whether 53-year-old Captain Shah may have hijacked his own plane as a political protest – to show support for Malaysia’s opposition leader, Anwar Ibrahim.

Co-pilot Fariq Abdul, 27, has also been investigated, and it has been revealed that on previous flights he invited passengers into the cockpit of the plane.

2. Al-Qaeda involvement in missing Malaysia Airlines flight MH370.

UK media are reporting that the plane hijacking could be linked to al-Qaeda.

The Telegraph reports that an al-Qaeda informer told courts last week that it was possible up to five Malaysian men had been planning to take over a plane – using a bomb hidden in the sole of a shoe to blast open the door to the cockpit. The Telegraph wrote that:

Security experts said the evidence from a convicted British terrorist was “credible”. The supergrass said that he had met the Malaysian jihadists – one of whom was a pilot – in Afghanistan and given them a shoe bomb to use to take control of an aircraft.

However, Mr Najib has said, “Despite media reports that the plane was hijacked, I wish to be very clear we are still investigating all possibilities as to what caused MH370 to deviate from its original flight path.”

3. Uighur separatists claim responsibility for missing Malaysia Airlines flight MH370.

Last week, Uighur separatists from China’s Muslim province claimed responsibility for the disappearance of the plane. But the claims were dismissed as not credible, despite the fact that a 35-year-old Uighur man was on board the plane.

However, Malaysian authorities have now said that the man undertook flight simulator training in 2005 – so the reports are being looked at in a new light.

Another fact that seems to support this theory is that Prime Minister Najib Razak has revealed it is possible that the plane disappeared up the “Kazakhstan‎ corridor”. The Uighur’s field of activity stretches from western China to Kyrgyzstan, which is directly beneath the corridor.

China has blamed Uighurs for two mass knife attacks over the past two weeks.

4. Pilot suicide attempt could be behind missing Malaysia Airlines flight MH370.

Investigators believe that a pilot suicide attempt could explain the disappearance of flight MH370.

The fact that the Malaysia Airlines jet communications were deliberately shut down to hide the location of the plane, suggests that whoever was in the cockpit knew what they were doing.

Although rare, there have been instances in the past of pilots crashing planes in an attempt to take their own lives. In 1997, a SilkAir Boeing 737 flying from Jakarta crashed into the water, and authorities eventually deemed the cause of the crash to be pilot suicide.

5. Malaysia Airlines MH370 could have landed in a remote area.

Some believe that the lack of plane debris indicates that Malaysia Airlines MH370 may have touched down – and the plane is hidden in a remote area.

Although the size of the plane (a Boeing 777) would make landing it surreptitiously very difficult, Paul Yap, aviation lecturer at Temasek Polytechnic in Singapore, told The Star that if whoever was flying the plane for that long was able to avoid radar detection, “that person should most likely be able to land it safely as well”.

David Kaminski-Morrow, air transport editor for Flight International, told The Star that “evidence of deliberate action does open several new leads, including the possibility that the aircraft is not lost at sea”.

UPDATE: Cyber-hijacking involved in MH370?

Some have also theorised that the disappearance of Malaysia Airlines MH370 could be the first ‘cyber-hijacking’ case ever.

Former Home Office scientific adviser Dr Sally Leivesley told Sunday Express in London that hackers may have been able to interfere with the plane’s cruising direction, altitude and speed. Dr Sally Leivesley said:

There appears to be an element of planning from someone with a very sophisticated systems engineering understanding. This is a very early version of what I would call a smart plane, a fly-by-wire aircraft controlled by electronic signals. It is looking more and more likely that the control of some systems was taken over in a deceptive manner, either manually, so someone sitting in a seat overriding the autopilot, or via a remote device turning off or overwhelming the systems.

A mobile phone could have been used to do so or a USB stick. When the plane is air-side, you can insert a set of commands and codes that may initiate, on signal, a set of processes.

The fate of those on board MH370 is still unclear, and the world waits – along with the devastated families and friends of the missing passengers – for this mystery to be solved.

Mamamia will provide further details as they emerge.