Authorities also found drug paraphernalia and prescription drugs, ABC reports.
The Oscar-winning actor was found by a friend on the bathroom floor of his apartment Sunday morning with a syringe in his arm. He was pronounced dead at the scene. No cause of death has been determined and police is still currently investigating.
An autopsy is scheduled for Monday, according to CNN.
Hoffman has struggled with drug addiction for years and entered a detox facility for heroin last spring. He had been sober for 23 years prior.