"Someone is hiding something. It is not fair that Malaysian Airlines (MAS) and Malaysia should take the blame," he said in his blog Chedet.cc.
In his blog, Mahathir expressed his viewpoints and theories on the missing plane that vanished mysteriously on March 8 with 239 people on board and stressed that something was out of place and that the media would not post anything about Boeing or the Central Intelligence Agency.
"What goes up must come down. Airplanes can go up and stay up for long periods of time. But even they must come down eventually. They can land safely or they may crash. But airplanes don't just disappear," he said.
"Certainly not these days with all the powerful communication systems which operate almost indefinitely and possess huge storage capacities," the 88-year-old leader said.
Last week, Prime Minister Najib Razak had admitted that Malaysia "did not get everything right" in the first few days of MH370's disappearance and called for implementing real-time tracking of airliners.
Malaysia believes the Beijing-bound Boeing 777-200 plane was deliberately diverted by someone on board and that satellite data indicates it crashed in the Indian Ocean, west of the Australian city of Perth.
Stating that he believes the tracking system on the plane was intentionally disabled, Mahathir, who was Malaysian prime minister from 1981 to 2003, questioned on where was the data of the plane, which was supposed to have been recorded by the satellite.
"MH370 is a Boeing 777 aircraft. It was built and equipped by Boeing, hence all the communications and Global Positioning System (GPS) equipment must have been installed by Boeing.
"If they failed or have been disabled, Boeing must know how it can be done and surely Boeing would ensure that they cannot be easily disabled as they are vital to the safety and operation of the plane," he said.
He claimed that in 2006, Boeing received a US patent for a system that, once activated, removes all control from pilots to automatically return a commercial airliner to a pre- determined landing location.