Jonah Hill's Brother Dead at 40, Investigated As Possible 'Accident' Involving 'Substance'

Jordan Feldstein, the brother of Jonah Hill, passed away Friday at 40-years-old, and investigators believe he may have ingested a substance that contributed to his death.

Law enforcement sources tell us 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 investigators related to ingesting some sort of substance or substances. At this point, it is not being handled as a natural death.

We're told it's unclear what the substance is at this point, but the coroner will be doing toxicology as part of the death investigation.

His family says the cause of death is a "heart attack."

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

His family told Variety he called 911 Friday night to his Beverly Hills home for shortness of breath, and went into full cardiac arrest and passed away shortly thereafter.

The coroner will be handling the death investigation going forward.

He leaves behind two children.

R.I.P.