Producer Bobby Heyward, 30, died June 20 of what has been allegedly reported as a drug overdose.
According to US Weekly, the Los Angeles Coroner's office confirmed the death, but has not revealed the official cause.
Heyward, Odom and Sangouthai were part of a close knit group of friends.
Just three days before his death, Heyward posted a photo of the three on Instagram, mourning after his friend's death.
The post read: "#RIP To my big brother Jamie who always brought light into any room he walked into and laughter as well at all times J you will always be missed. Family for life. #BandOfBrothers."
Sangouthai reportedly died of a drug overdose on June 14.