The investigation into the disappearance of the flight has turned to investigating the pilots and the flight engineer on board the aircraft, and a flight simulator and computer have been confiscated from the flight engineer's home.
The theory being posed in the Telegraph newspaper and other outlets is that the plane may have been hijacked as a tool in a terror plot that would involve flying it into a building, causing mass casualties like those in the 9/11 terrorist attacks in New York, Washington, and Pennsylvania.
According to the testimony in the trial of Osama Bin Laden's son-in-law and Al-Qaeda spokesman Sulaiman Abu Ghaith, a plot was mentioned in which a person would use a shoe bomb to gain access to the cockpit and then use the plane to hit a target. One of the possible targets mentioned in the testimony were the Petronas Towers in Kuala Lumpur.
The Petronas Towers are the tallest twin towers in the world and were the tallest buildings in the world until they were surpassed in 2004.