NEW YORK CITY, NEW YORK: Robert De Niro's grandson Leandro De Niro's official cause of death has been revealed. The teenager's mother Drena De Niro confirmed his death at the age of 19 on July 2.

Drena, who was adopted by Robert, also shared an emotional note following her son's death as she wrote, "My beautiful sweet angel. I have loved you beyond words or description from the moment I felt you in my belly. You have been my joy my heart and all that was ever pure and real in my life. I wish I was with you right now. I wish I was with you."

What is Leandro De Niro's official cause of death?

According to the information obtained by TMZ, New York City's chief medical examiner confirmed on Tuesday, August 8 that the 19-year-old had fentanyl, alprazolam, bromazolam, ketamine, 7-amino clonazepam, and cocaine in his system and the toxic combination has led to a ruling his death an accidental overdose.

In the emotional statement dedicated to her son, Drena who is a filmmaker mentioned her ex-partner and artist Carlos Mare with whom she shared Leandro, and wrote, "I’m so sorry my baby, I’m so sorry @carlosmare. Rest in Peace and Eternal Paradise my darling boy."

Mare then commented on her post and wrote, "My dear Drena … words aren’t enough to express the joy he gave us or the loss we now endure with our families and friends. He is Godschild now. On this full moon, his spirit luminates what could not be seen in the dark. You can’t spell LOVE without LEO."

Suspect who allegedly sold drugs to Leandro was arrested

Since Leandro's tragic death, Drena had previously responded to a social media user who asked her the reason behind her son's death before the official cause was revealed. She claimed that someone sold her son fentanyl-laced pills.

"Fentanyl-laced pills that they knew were laced yet still sold them to him so for all these people still f*****g around selling and buying this s**t, my son is gone forever," Drena wrote in July, the same month when a 20-year-old woman name Sofia Haley Marks was arrested for allegedly selling Leandro drugs and was charged with federal drug distribution.

Following the death of his oldest grandson, Robert also penned an emotional tribute. "I’m deeply distressed by the passing of my beloved grandson Leo. We’re greatly appreciative of the condolences from everyone. We ask that we please be given privacy to grieve our loss of Leo," the 'Godfather' actor wrote in a statement to US Weekly.