When Michael Jackson collapsed and died at his rented mansion in the Hollywood Hills last month, both of the singer’s arms were “riddled with marks,” and the veins had collapsed, sources tell CNN.

These characteristics are frequently found in intravenous drug users.

According to a source close to the investigation into what caused Michael Jackson’s fatal heart attack, the legendary singer had “numerous track marks” on his arms, which “could certainly be consistent with the regular IV use of a drug, like Diprivan.”