The 19-year-old grandson of Robert De Niro, Leandro De Niro Rodriguez, died after being sold fentanyl pills, his mother said. The actor’s eldest daughter, Drena De Niro, announced Leandro’s death on Monday, saying the family had lost a “sweet angel,” but the cause of death was not released at the time.

However, later responding to a comment on Instagram, in which a user asked how her son died, the 51-year-old wrote, among other things: “Someone sold him fentanyl pills.”

View this post on Instagram

A post shared by Drena (@drenadeniro)

The synthetic opioid fentanyl, a legal prescription painkiller, is now a black market product. Cheap, up to 100 times more potent than natural opioids, it’s just as deadly. The spread of fentanyl has been invisible, steady, and deadly, according to interviews with people involved in the sale of illegal drugs, where a large portion of fentanyl ends up on the “street market,” as well as interviews with law enforcement experts and addictions.

Fentanyl is mainly manufactured in China, which ships it either whole or in the form of raw ingredients (called precursors) to Mexico. That’s where it’s picked up by the cartels, according to Ben Westhoff, author of “Fentanyl, Inc. How Rogue Chemists Created the Deadliest Wave of the Opioid Epidemic”.

View this post on Instagram

A post shared by Drena (@drenadeniro)

A spokesperson for the New York City Police Department told NBC News that police received a call at approximately 2:23 p.m. Sunday. “The Office of the Chief Medical Examiner will determine the cause of death,” the police spokesman said.

Leandro De Niro Rodriguez followed in his mother and grandfather’s footsteps into acting. He had small roles in the films A Star Is Born, The Collection and Cabaret Maxime. De Niro adopted Drena as his daughter during his marriage to Diahnne Abbott.

View this post on Instagram

A post shared by Drena (@drenadeniro)