The autopsy findings were released for the first time Tuesday along with the crash investigation report.

Authorities are investigating how the substances might have affected the pilot at the time of the August crash. Morales, 30, was sentenced to three years probation on charges of crack cocaine possession 12 days before the crash.

Aaliyah, who was already a two-time Grammy nominee for best female R&B vocalist, was leaving the Bahamas following a video shoot when the Cessna 402-B crashed during takeoff. All nine people aboard died.

The aviation department also said Tuesday the aircraft may not have undergone fuel-pump wiring modifications required in August 1988. Unidentified particles and corrosion found in the fuel filters were "indications that routine maintenance was not being performed," the statement said.

The investigative committee has not yet been able to talk to the plane's owner of the airplane, or inspect the engine or aircraft log books, which would show maintenance, it said.

The twin-engine plane was also at least 700 pounds overweight, investigators have said. Although nine people were on board, the plane is certified to carry up to eight including the pilot.

Inspection of the plane's engine, airframe, propeller and fuel system, however, has shown no cause for malfunction, authorities said Tuesday.

In May, the parents of Aaliyah filed a lawsuit against Virgin Records, alleging that negligence and recklessness caused the plane crash.

The lawsuit, filed in Los Angeles Superior Court on behalf of Diane and Michael Haughton, also named several video production companies and Blackhawk International Airways, the company that operated the plane.

Neither Blackhawk nor Skystream, the plane's registered owner, had a permit to operate commercial charter flights in the Bahamas, investigators said.

Blackhawk officials couldn't be reached for comment.