Malaysia Airlines pilot Zaharie Ahmad Shah.

Malaysia Airlines pilot Zaharie Ahmad Shah. Photo: Facebook

A Malaysian police investigation into the disappearance of flight MH370 has identified captain Zaharie Ahmad Shah as the chief suspect, if human intervention is to blame.

After more than 170 interviews, the criminal inquiry cleared all others on board, including first officer Fariq Abdul Hamid, London's The Sunday Times reports.

Police have not out alternative causes, such as mechanical failure or terrorism - they simply suggest that if foul play is involved, Captain Zaharie is the likely perpetrator. He is known to have installed a flight simulator in his home, and police investigators now say he had programmed flights out into the Indian Ocean that involved landing on a small island airstrip. The data had been deleted from the simulator but police were able to recover it.

The criminal inquiry is continuing and these initial findings have only been selectively revealed to foreign governments and air crash investigators.

"To date no conclusions can be made as to the contributor to the incident and it would be sub judice to say so. Nevertheless, the police are still looking into all possible angles," Malaysian police told The Sunday Times.

Captain Zaharie had previously come under suspicion due to rumoured marital and financial instability. He was also said to be an enthusiastic supporter of Malaysia's opposition leader Anwar Ibrahim, whose 2012 acquittal on sodomy charges had just been overturned. But Slate reports Mr Anwar's People's Justice Party is a politically moderate group and there is little evidence Captain Zaharie was a 'fanatic', as he has sometimes been described.

Flight MH370 disappeared on March 8 and no trace of the jet has been found. Dutch investigators are now mapping the ocean floor in an effort to better co-ordinate the next phase of the search.