Robert De Niro’s 19-year-old grandson Leandro De Niro Rodriguez died after taking pills laced with fentanyl, his heartbroken mom has claimed.

The teenager’s death is being probed as a possible overdose after his lifeless body was discovered inside a Lower Manhattan apartment Sunday with a white, powdery substance and drug paraphernalia nearby, police sources said.

While the toxicology report is still pending, his grief-stricken mom, Drena De Niro, has alleged someone knowingly sold her son tainted drugs.

“Someone sold him fentanyl laced pills that they knew were laced yet still sold them to him,” Drena, 51, wrote on Instagram Tuesday in response to a comment asking about the cause of her son’s death.

“So for all these people still f–king around selling and buying this s–t, my son is gone forever,” she added.

The city Office of the Chief Medical Examiner has yet to disclose an official cause of death, but sources said NYPD detectives in Narcotics Borough Manhattan South have been brought in to probe the case — a sign they could be investigating who, if anyone, provided the drugs.

NYPD Chief of Detectives James Essig told reporters last month that fentanyl is now “laced in probably 98% of the drugs” in the Big Apple.

“Fentanyl is in everything now, everything,” Essig said. “Now people have low tolerance, that’s why they’re overdosing so much.”

Meanwhile, Drena — who is De Niro’s eldest daughter with his ex-wife Diahnne Abbott — has shared several tributes on Instagram in the wake of her son’s death.

“I can barely type through my tears but all the love, the messages, calls, texts, emails, the friends and family that held me up these last 24 hrs I’ve not been able to respond yet but we’re grateful for the all your love and condolences,” she wrote Monday evening.

None of this is right or fair and my heart hurts in a way I never knew possible while still breathing and barely functioning. Leo my darling I love you today like the first day I held you in my arms.”

She continued: “The same man that picked us up from the hospital when you were born drove us to the funeral home where I touched and held you for the last time.”

Her Oscar-winning father issued a statement of his own on Monday, saying: “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.”

Culled from New York Post