"Monkees" singer Davy Jones died with cannabinoids in his system -- a class of drug that includes marijuana -- this according to his autopsy report.
It's unclear if the cannabinoids in question were from smoking marijuana, or from something else entirely -- but the report is clear ... the cannabinoids did NOT play a role in Davy's death.
The toxicology report came back negative for other drugs.
The report also confirms what TMZ first reported ... Davy died of a heart attack -- with severe build-up in his arteries.
As we first reported, Davy suffered the heart attack in February, while visiting his horses at a Florida ranch. He was pronounced dead shortly after at a nearby hospital.
Davy was 66.