The beloved U.S. comic died in March (16).

The report, obtained by TMZ, suggests a blood clot that travelled from his leg into his lungs ended his life.

He also had an enlarged heart. The cause of death is listed as "natural" and an "accident".

Shandling had Xanax, painkiller hydrocodone, and oxycodone in his system at the time of his death.

The Larry Sanders Show star was 66.