Robert De Niro's 19-Year-Old Grandson Leandro's Official Cause of Death Revealed

Leandro died on July 2 in New York City.

Robert De Niro's 19-year-old grandson Leandro's official cause of death has been released a month after his tragic death

According to New York City's chief medical examiner, Leandro died of an accidental overdose from the toxic effects of fentanyl, bromazolam, alprazolam, 7-aminoclonazepam, ketamine, and cocaine. 

Leandro died on July 2 in NYC. After his death, his mother, Drena -- the 51-year-old daughter of the iconic actor -- shared the heartbreaking news on Instagram. 

"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 . I don’t know how to live without you but I’ll try to go on and spread the love and light that you so made me feel in getting to be your mama," she wrote. "You were so deeply loved and appreciated and I wish that love alone could have saved you 😞I’m so sorry my baby , I’m so sorry @carlosmare 😢💔. Rest in Peace and Eternal Paradise my darling boy 🙏🏽💔💔💔💔💔🕊️🕊️🕊️🕊️"

Drena later told ET 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."

At the time, the grieving mother later shared what she believed to be the cause of death.

"Someone sold him fentanyl laced pills that they knew were laced yet still sold them to him," Drena wrote in an Instagram comment, replying to a follower who asked, "OMG, why? How?"

"So for all these people still f**king around selling and buying this s**t, my son is gone forever," she concluded with a crying emoji. 

In a statement to ET, De Niro also spoke out following his grandson's death.

"I'm deeply distressed by the passing of my beloved grandson Leo," the statement read. "We're greatly appreciative of the condolences from everyone. We ask that we please be given privacy to grieve our loss of Leo."

Leandro was laid to rest on July 8 in New York City, just a week after his death. De Niro and the rest of his family and friends were seen leaving the Frank E. Campbell Funeral Home in Manhattan before heading to the cemetery in Valhalla, New York. 

De Niro's father is buried at the same cemetery in Valhalla.