The shocking news of Michael K. Williams’ death rippled through the Internet yesterday. Tributes have flooded the timeline from collaborators and friends to fans who’ve expressed just how much the actor meant to them.

A cause of death has yet to be confirmed but police are reportedly conducting an investigation into his passing as a suspected overdose. According to TMZ, this has sparked an investigation into the potential drug dealer who sold to Williams. The publication says their police sources said they found drug paraphernalia at the scene of Williams’ death over the weekend. They believe that Williams’ was sold some sort of heroin-based substance.

Police will have to wait a few weeks until a toxicology report can confirm that he died from an overdose. The official autopsy hasn’t been conducted yet, either but police and detectives do believe that there were drugs involved.

Earlier today, Vice revealed that Michael K. Williams had been in the midst of filming the second season of his series Black Marketat the time of his passing. Though the majority of the season had been taped, they will be re-routing their plans to release the final season.

Williams’ extensive acting resume included The WireBoardwalk EmpireLovecraft Country, When They See Us, and more.

We’ll keep you updated on more information surrounding the investigation.