Suspicious data was recovered from the flight simulator belonging to the pilot of doomed Malaysian Airways flight MH370, Australian officials have confirmed, after confidential FBI documents were leaked to the press.

Australia's Joint Agency Coordination Centre, which is overseeing the search for the plane off the Australian coast, has said in a statement that the captain of MH370, Zaharie Ahmad Shah, had appeared to have conducted a flight, on this simulator, to the southern Indian Ocean less than a month before the plane vanished along a similar route, AP reported.

However, in an ambiguous statement, the agency cautioned evidence of the route did not prove that Zaharie had planned to steer the plane off course and showed only "the possibility of planning" for such an event.

The possibility Shah may have planned a suicide flight was raised by New York Magazine citing an FBI investigation. 230 people died aboard the Boeing 777 when it disappeared while flying from Kuala Lumpur to Beijing in March 2014.

The US publication referred to FBI documents which alleged Ahmed had plotted a course into the deep southern Indian Ocean on a home flight simulator. The course the FBI was able to recover stored by Microsoft's Flight Simulator X programme closely matched the final flight MH370 took before it disappeared.

However, Malaysia has cleared Shah of any wrongdoing and withheld the FBI's findings from its final report. There has been confusion over whether Malaysian authorities ever received the information. Malaysia's national police chief, Khalid Abu Bakar said Malaysian police had never handed any such document or information. On the other hand, Malaysia's own transport minister confirmed two years ago that Malaysia was working with the FBI to analyse data from the simulator's hard drives.

Shah's family have refuted the conclusions drawn from the data. Speaking to CNN, Sakinab Shah, the pilot's sister said the claims were a "fabrication" and complained her brother had been "scapegoated".