Robert De Niro's grandson Leandro's cause of death confirmed

Split-screen of Robert De Niro and his late grandson Leandro
De Niro's grandson was found unresponsive and pronounced dead on July 2. Photo credit: Getty Images

Robert De Niro's grandson, Leandro De Niro Rodriguez, died of an accidental drug overdose, it has been confirmed.

The 19-year-old aspiring actor was found unresponsive and pronounced dead by emergency services on July 2.

On Tuesday (local time), the New York City chief medical examiner's office confirmed the cause of death.

According to the medical examiner, Leandro's passing resulted from the "toxic effects of fentanyl, bromazolam, alprazolam, 7-aminoclonazepam, ketamine, and cocaine".

His manner of death was ruled an accident.

Leandro's mother, Drena De Niro, previously spoke out to share her beliefs on the cause of her son's death, claiming he had been sold pills laced with fentanyl.

Fentanyl is a highly potent synthetic opioid 50 to 100 times stronger than morphine.

"Someone sold him fentanyl laced pills that they knew were laced yet still sold them to him, so for all these people still f**king around selling and buying this s**t, my son is gone forever," the 51-year-old wrote on Instagram.

In mid-July, a 20-year-old woman was arrested in connection with Leandro's death and accused of selling him drugs. Her trial is expected to begin later this month.

Drena announced Leandro's death in a statement: "It is with immeasurable shock and sadness that we say goodbye to our beloved son Leo. We thank you for the outpouring of love and support and ask that we are given privacy at this time to process this inconsolable grief."