Three years on, MH370 remains a puzzle

The third interim statement on the progress of the probe into the missing Boeing 777 also noted there was insufficient information to determine if the plane broke up mid-flight or on impact with the ocean.

"With the aircraft wreckage and flight recorders still not found, there is a significant lack of vital evidence available to the investigation team to determine with any certainty, the reasons the aircraft diverted from its filed flight plan route," it said.

The statement was released in conjunction with the third anniversary of the incident which saw the plane vanish with 239 people aboard on March 8, 2014, en route from Kuala Lumpur to Beijing.

On April 25, 2014, Malaysia established an independent air accident investigation team, formally known as the 'Malaysian ICAO Annex 13 Safety Investigation Team for MH370', to probe the disappearance of Flight MH370.

The statement noted that other than the right flaperon, a part of the right outboard flap and a section of the left outboard flap were confirmed to be from the missing aircraft.

A few other pieces of debris were determined to be almost certain from Flight MH370, and they included some cabin interior items.

The statement said damage examination on the recovered part of the right outboard flap, together with the damage found on the right flaperon, led to the conclusion that the flaps were most likely in the retracted position.

Recovery of the cabin interior debris, it said, suggested the plane was likely to have broken up, adding however, there's insufficient information to determine if the aircaft broke up in the air or upon impact with the ocean.

It said additional parts were still being found along the coasts of southeast Africa, and the examination of these items were continuing.

It said that despite the limitations in available evidence, the investigation had identified several key issues within the civil aviation system that could be improved to enhance safety in the future.

Based on available information, the statement noted the investigation team was presently working towards finalising its analysis, findings and conclusions, as well as safety recommendations on eight areas associated with the disapperance of Flight MH370.

The areas being reviewed by the team are diversion from the filed flight plan route, air traffic service operations, flight crew profile, airworthiness and maintenance and aircraft systems; and satellite communications, wreckage and impact.

The rest are organisation and management information of the Department of Civil Aviation Malaysia and Malaysia Airlines, and aircraft cargo consignment.

The investigation team comprises 19 Malaysians and seven accredited representatives of seven safety investigation authorities from as many countries.

The first and second interim statements were issued on March 8, 2015 and March 8, 2016, respectively.

Meanwhile, a private remembrance ceremony was held at the KL International Airport in memory of Flight MH370, in the presence of airline employees as well as family members of the staff aboard the missing plane.

The underwater search for the aircraft in southern Indian Ocean was suspended on Jan 17.