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Sylvester Stallone's 36-year-old son Sage was memorialized in a private ceremony Saturday at St. Martin of Tours Catholic Church in Brentwood, Calif.

Sylvester Stallone and Sage's mother, Sasha Czack, led a small procession of mourners, according to The New York Daily News.

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Sage Stallone was found dead in his Los Angeles apartment July 13. The cause of death is unknown, pending the results of toxicology tests.

The family of the actor and son of action-star Sylvester Stallone met with the Los Angeles County Coroner's Office Tuesday and expressed worry that Sage Stallone might have been over-medicated before his death. The meeting reportedly focused on the status of the investigation.

The Los Angeles Police Department's robbery-homicide division had been brought into the investigation, but officials said it remained primarily a coroner's investigation and that there were no signs of foul play.

ABC News' Sheila Marikar contributed to this report.