(CNN) Traces of explosive material were found on the remains of the victims of the EgyptAir Flight 804 crash, the Egyptian investigation committee announced Thursday, citing a forensic report.
The Airbus A320 was en route from Paris to Cairo when it crashed into the Mediterranean Sea on May 19, killing 66 people. Authorities are still working to piece together exactly what caused the crash.
Egyptian officials previously had said a terror attack or technical failures could have downed the plane.
Details have been emerging about the doomed flight for months.
A senior source from the airline told CNN in July that the plane's cockpit voice recorder indicated there was a fire on board -- and an attempt to put it out -- before the aircraft plunged into the sea.
Now the case has been referred to Egypt's general prosecutor, officials said Thursday.
France's foreign ministry said it hopes the transfer of the case means the victims' remains will be returned to their families "as quickly as possible." There were 15 French people aboard the flight, and families have been pushing for months for their remains to be released.