PETALING JAYA, June 15 — Since MH370 first disappeared, experts and conspiracy theorists alike have been wracking their brains, trying to piece together what actually happened on March 8.

Everything — from a mistaken target to terrorism to former prime minister Tun Dr Mahathir Mohamad’s belief the CIA was behind the plane’s disappearance — was thrown in the ring for public debate.

The most popular theory had been based on the most credible evidence to date — that one of the crew members was suicidal.

Most of the focus had been on Capt Zaharie Ahmad Shah but co-pilot Fariq Abdul Hamid also came under scrutiny.

For weeks, the Malaysian authorities were bombarded by questions about the possibility that Zaharie, who was said to be a strong supporter of Opposition Leader Datuk Seri Anwar Ibrahim, taking down the plane as a way to get back at the government.

His private life was laid bare as police went through his flight simulator and conducted background research to see if he may have had any reason to commit suicide.

However, MAS’s commercial director, Hugh Dunleavy, rejected this theory and said the captain was a seasoned pilot with an excellent record.

Dunleavy was reported to have said there were nothing to suggest the pilot was the one to blame.

The police then said hijacking was an angle they were investigating after checks on the passengers’ manifest revealed two passengers on the plane had boarded with stolen passports.

Interpol’s database showed that the passports used by Pouria Nour Mohammad Mehrdad, 19, and Delavar Seyed Mohammadreza, 29, were stolen from an Austrian and an Italian in Thailand.

The duo were cleared after police found that neither had a criminal record and that both had bought tickets to get to Europe, where it was believed they hoped to obtain asylum.

A more mechanical theory was introduced by aviation expert Ron Bishop, who said a fire or some other accident could have led to a gradual decompression of the plane.

He also said the pilots may have attempted to fly back to Malaysia but passed out after turning the plane which continued flying until it ran out of fuel.

New Zealand oil rig worker Mike McKay claimed he saw a burning plane going down the Gulf of Thailand at the time the plane disappeared.

McKay contacted his employer and Vietnamese authorities to inform them of the sighting, but his private e-mail was leaked and an author, Nigel Cawthorne, decided to expand on it.

Cawthorne said that at the same the plane went missing, a series of war games involving Thailand, the US, China, Japan, Indonesia and others were taking place in the South China Sea.

According to him, the plane might have been shot down by one of the weapons used in the game.

This last theory that came up was the plane landed on either the Andaman or Nicobar island off India.

The two islands lie between Indonesia and the coast of Thailand and Myanmar, of which military radars were said to might not even have been operating as the threat level was generally low.

This was dismissed by a newspaper, which said that if the plane had landed there, it would have been spotted.

However, a former BA777 pilot, Steve Buzdygan, said there were more than 570 islands around the area, and only 36 were inhabited.

“It is an isolated spot and landing may be difficult but not impossible,” he said.