Cause of Death for Jonah Hill's Brother Deferred Pending Further Investigation

The cause of death of Jordan Feldstein, Jonah Hill's older brother, has been deferred pending investigation, The Blast reports.

According to Feldstein's death certificate, Feldstein was buried at Hillside Memorial Park in Culver City, CA on December 26. Feldstein passed away on December 22. He was 40 years old.

As previously reported, law enforcement sources said that Feldstein's death is being investigated as a "possible accident or suicide" and the LA County Coroners office is conducting tests to find out if the death is related to ingesting some sort of substance.

In their initial statements, Feldstein's family said that the acclaimed music producer had died of a heart attack, though The Blast reports that sources close to the investigation say that substance abuse was likely a factor.

Investigators say that Feldstein's friends and family have told them he had a history of both heart issues and substance abuse. It's unclear which contributed to his death, or if perhaps it was a combination of the two. An early report stated that paramedics believed Feldstein had ingested a "substance" prior to his death, and that it was not being treated as a natural passing.

Feldstein called 911 when he began experiencing shortness of breath, and investigators now believe this was most likely an accident.

"Unfortunately, last night Jordan called 911 for shortness of breath," Feldstein's family said in a public statement on Friday. "When paramedics arrived it was determined he went into full cardiac arrest and passed away shortly thereafter. His family asks for privacy during this difficult and unexpected time. In lieu of food and flowers, the family will announce a charity in the coming weeks where memorial donations can be made in Jordan's name."

Feldstein was six years older than his brother, Jonah Hill, who has yet to comment on the tragedy. Their younger sister, Beanie Feldstein, stars alongside Saoirse Ronan in this year's hit movie Lady Bird.

Feldstein was the longtime manager of Maroon 5, as well as other musicians Miguel, Elle King and Robin Thicke.