Mr Najib said the government has “pretty conclusive” intelligence reports about what happened to the jet carrying 298 people but evidence must be collected so that it can be proven beyond a doubt if the case goes to court, AP reported.
The plane plunged on July 17 while flying from Amsterdam to Kuala Lumpur over an area of eastern Ukraine controlled by pro-Russia separatists.
Searches of the crash site were halted Aug 6 due to concerns that fighting in the immediate area was a threat.