Autopsy Reveals Robert De Niro's 19-Year-Old Grandson Died From Accidental Overdose of Cocaine and Fentanyl

The cause of death for Robert De Niro's grandson has been revealed, RadarOnline.com has learned.

Leandro De Niro Rodriguez, 19, was found unresponsive in a New York City apartment on July 2. Police said a mirror containing a "white powdery substance" was near Rodriguez's body in the apartment.

After it was revealed the teen's death was being investigated as a potential overdose, the medical examiner's report released Monday confirmed that a fatal dose of illicit substances led to his unexpected death.

The New York City chief medical examiner's report labeled Rodriguez's death as an accidental overdose, citing the toxic effects of fentanyl, bromazolam, alprazolam, 7-aminoclonazepam, ketamine, and cocaine contributed to his passing.

Police investigators previously confirmed that a bag of cocaine was found with Rodriguez, along with a straw containing residue, seven rectangular pills believed to be Xanax, and two unidentified blue pills.

Prior to the release of the chief medical examiner's report, officials said they believed drug dealers sold Rodriguez counterfeit drugs, including Xanax and hydrocodone pills, mere days before his death.

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The Xanax pills were allegedly laced with fentanyl, a rapidly growing factor in overdose deaths.

Rodriguez's mom, Drena De Niro, previously wrote on Instagram that her son was sold "fentanyl-laced pills" and claimed the dealers "knew were laced yet still sold them to him."

After Rodriguez's death, NYPD launched a manhunt for the dealers responsible for the fentanyl-laced pills. Less than two weeks after his accidental overdose, the police arrested a woman, known as "Princess Percocet," in connection to the laced drugs.

Sophia Haley Mark, 20, was held without bail on federal narcotics charges. An underground sting operation conducted with the combined effort of the NYPD, Homeland Security and the Drug Enforcement Administration (DEA) led to Mark a.k.a. Princess Percocet's arrest.

According to her criminal indictment, Mark was accused of selling counterfeit pills to Rodriguez. Text messages between the two revealed that Mark told Rodriguez, "I don’t wanna kill u."

Texts from the days leading up to his death also revealed that Mark tried to talk Rodriguez out of the sell when he messaged about buying "thirties" — counterfeit Oxy pills — on June 30.