US actor Michael K. Williams, who starred as Omar Little in the widely acclaimed television series The Wire, died of an accidental drug overdose, authorities said Friday.

The 54-year-old, who played the iconic Baltimore stick-up man in the groundbreaking show, was found dead earlier this month in his apartment in New York.

The New York City Office of Chief Medical Examiner said in a statement that the cause of Williams’ death was “acute intoxication by the combined effects of fentanyl, p-fluorofentanyl, heroin and cocaine.” The death was an accident, according to officials.

The Emmy-nominated actor had been widely hailed for his role in The Wire, in which he played an armed robber. He received multiple Emmy nominations for his work on various shows and films.

The series became one of the most popular shows on television and ran through five seasons from 2002 until 2008.

Williams was also well-known for the role of Albert ‘Chalky’ White on the HBO series Boardwalk Empire, among others.

Williams had spoken openly of his past struggles with addiction.

His work playing Omar attracted the attention of a future president, with the-then senator Barack Obama calling Williams’ role in The Wire his favourite and “a fascinating character.”

Williams’ role was enhanced by a facial scar he said he received during a New York street fight on the night of his 25th birthday, when a man slashed him with a razor.

He told NPR in an interview the pronounced scar actually helped advance his career, as he climbed from being a back-up dancer in music videos for stars such as Madonna and George Michael to getting speaking roles playing rough characters in drama shows.