An independent investigative report released Monday offered no definitive answers about what happened to Malaysia Airlines Flight 370, but suggested that a third party may have played a role in its disappearance more than four years ago.
Kok Soo Chon, the chief investigator, told reporters that the team of 19 international investigators did not uncover evidence that the pilots or any of the passengers could have been behind the disappearance.
"We cannot rule out unlawful interference by a third party," Kok said, according to The Associated Press. But he added that no outside group has claimed responsibility for hijacking the flight.
The report also reaffirms the Malaysian government's assertion that the flight was deliberately re-routed and continued flying for hours after losing communications, the AP reported.
MH370 disappeared in March 2014 during a flight from Kuala Lumpur to Beijing. It was carrying 239 people.
Sparse remnants of the plane have been found washed ashore in Africa and islands throughout the Indian Ocean, suggesting that the flight went down in a remote part of the southern Indian Ocean.
The plane's black boxes, which record flight data, have not been found.
Searches by the governments of Australia, Malaysia and China have all failed to turn up definitive answers about what happened to the flight, and a Texas-based private company hired by Malaysia to find the wreckage — Ocean Infinity — ended its search in May without success.