Authorities Find 50 Bags of What is Thought To Be Heroin in Philip Seymour Hoffman's Apartment

The actor was found dead in his Manhattan apartment yesterday

(CNN) -- [Breaking news update, posted at 10:59 a.m. ET]

Authorities investigating the death of actor Philip Seymour Hoffman found close to 50 bags containing what is believed to be heroin in his apartment, two law enforcement sources familiar with the probe said Monday. Investigators also found several bottles of prescription drugs, and more than 20 used syringes in a plastic cup, the sources said.