Last month, actor Chris Penn, the younger brother of Sean Penn, was found dead at his home in the Santa Monica area (read the story).

At the time no cause could be listed, and it was all purely speculation as to what actually happened. Police did not suspect foul play, and the initial autopsy listed his official cause of death as an enlarged heart.

This week, the newly-released toxicology reports shed more light on Penn's passing.

At the time of his death, it appears there were several chemical substances in his system, both legal and not. Reports show he had traces of morphine, Valium, Promethazine (an antihistamine) and marijuana present, as well as an substantial presence of codiene.

This chemical cocktail, along with health problems the actor was already suffering, are what lead to what authorities are ruling an accidental death.

At his passing, Penn weighed over 300 pounds, and already had heart-related problems that were threatening his life. It is speculated the addition of the drugs in his body were just too much for his bad heart to take.

The original cause of death, the enlarged heart, will remain on record.

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