Sage Stallone -- Autopsy Complete, Results Pending Toxicology Report

UPDATE 1:35 PM PT -- The autopsy has been completed, but the results will be deferred pending a toxicology report, which usually takes 4-6 weeks.

The L.A. County Coroner has just begun the autopsy of Sage Stallone ... TMZ has learned.

According to our sources, it will be completed later today.

As TMZ first reported, the son of Sylvester Stallone was found dead in his home on Friday of an apparent overdose. His body was discovered by the maid.

Law enforcement sources tell TMZ they believe his death was accidental and no note was found at the scene.