Updated

Michael K. Williams' cause of death has been determined, Fox News can confirm. 

The NYC Office of Chief Medical Examiner told Fox News in a statement on Friday, the actor died from an "acute intoxication by the combined effects of fentanyl, p-fluorofentanyl, heroin and cocaine." His manner of death was ruled an accident.

"The Wire" star was found dead on Sept. 6 by family members in his Brooklyn apartment. He was 54 years old.

Williams was a ubiquitous character actor in other shows and films for more than two decades, creating another classic character as Chalky White in HBO's "Boardwalk Empire" from 2010 to 2014, and appearing in the films "12 Years a Slave" and "Assassin’s Creed." 

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He also appeared in "The Night Of" and "Lovecraft Country" for which he was nominated for an Emmy Award. 

Michael K. Williams died from an accidental drug overdose, according to the NYC Chief Medical Examiner.  (REUTERS/Ringo Chiu)

Williams was born in 1966 in Brooklyn, the son of a mother from Nassau, Bahamas, and a father from South Carolina. He was raised in the Vanderveer Projects in East Flatbush, Brooklyn, and went to George Westinghouse Career and Technical Education High School.

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His first forays into entertainment were as a dancer for artists including Missy Elliot, Ginuwine, Crystal Waters and Technotronic.

"I was angry and I had a lot of energy," he told The Associated Press in 2018. "It was such an outlet. I was not the best dancer, you know, by far, but I was definitely the most passionate. I always had this energy. You always felt me whether I was in sync or not with the other guys."

Williams had been working with a New Jersey charity to smooth the journey for former prison inmates seeking to reenter society, and was working on a documentary on the subject.

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He spoke in an Associated Press story in 2020 of his rough time growing up, and said he had struggled with drug addiction, which he had spoken frankly about in interviews in recent years.

"This Hollywood thing that you see me in, I’m passing through," he said. "Because I believe this is where my passion, my purpose is supposed to be."

If you or someone you know is struggling with mental health or drug addiction, please contact the Substance Abuse and Mental Health Services Administration at 1-800-662-HELP (4357).

The Associated Press contributed to this report.