Just days after the tragic passing of Robert De Niro's grandson, more details surrounding a potential cause of death are being revealed.

De Niro's eldest child, Drena De Niro, discussed her son Leandro's passing in the comments section of her Instagram, replying to a user who asked what happened.

"Someone sold him fentanyl laced pills that they knew were laced yet still sold them to him, so for all these people still f---ing around selling and buying this s--- , my son is gone forever," she wrote.

A representative for both De Niros additionally told Fox News Digital, "No comments are being made at this time."

ROBERT DE NIRO 'DEEPLY DISTRESSED' BY DEATH OF 19-YEAR-OLD GRANDSON

Robert De Niro looks up in a suit

Robert De Niro's grandson Leandro passed away earlier this week. He was just 19. (Christophe Simon/AFP)

Drena previously announced that her son, Leandro De Niro Rodriquez, had passed away in a heartbreaking post to Instagram.

"My beautiful sweet angel," she began. "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.

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In a statement obtained by Fox News Digital, De Niro, 79, commented on the devastating loss.

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

ROBERT DE NIRO'S DAUGHTER POSTS TRAGOC TRIBUTE TO HER 19-YEAR-OLD SON: ‘YOU DIDN’T DESERVE TO DIE LIKE THIS

Drena also shared her grief in a statement to Fox News Digital, "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." 

Actor Robert De Niro sits next to his daughter Drena

Drena De Niro says that her son was given drugs known to be laced with fentanyl. (Dimitrios Kambouris/Getty Images)

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In response to Fox News Digital's questions about his death, a DCPI spokesperson shared that they responded to a 911 call on July 2, where "an 18-year-old male was found unconscious, unresponsive and was pronounced deceased by EMS on scene." A cause of death will be determined by the medical examiner's office.

A DCPI spokesperson was not immediately available for comment regarding if the case is being investigated as an overdose or if there are any suspects.

Drena De Niro with dad Robert De Niro

Robert De Niro adopted his daughter Drena while married to first wife Diahnne Abbott. (Gregg DeGuire/JB Lacroix)

Drena is De Niro's eldest child. She was adopted by the actor when he was married to her mother, his ex-wife Diahnne Abbott, from 1976-1988. 

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De Niro recently welcomed his seventh child, a daughter Gia, with girlfriend Tiffany Chen.