(Carlo Allegri/AP Photo)

Michael Clarke Duncan, the Oscar-nominated actor who suffered a heart attack in July, died today. He was 54.

A representative for Duncan's fiancee, reality-TV personality Omarosa Manigault-Stallworth, said in a statement that Duncan passed away in Los Angeles.

Duncan "never fully recovered" from his July 13 heart attack, the rep told ABC News, adding that "Manigault is grateful for all of your prayers and asks for privacy at this time. Celebrations of his life, both private and public, will be announced at a later date."

Manigault-Stallworth, a former star on the NBC reality series "The Apprentice" had been dating Duncan since 2010.

Duncan was best known for his role as John Coffey in "The Green Mile," for which he was nominated for an Oscar and a Golden Globe. He also appeared in "Armageddon," "Planet of the Apes," "Sin City," and "The Whole Nine Yards," among other movies.

Before his heart attack, Duncan appeared in a PSA advocating the importance of knowing early onset symptoms of strokes.

Duncan's role in "The Green Mile," alongside Tom Hanks, propelled him into the upper echelons of Hollywood. Roger Ebert called his portrayal of a paranormally enabled child killer "both acting and being."

Duncan hadn't been far removed from his previous career doing manual labor when "The Green Mile" won over critics.

When asked about the film's success, he told Hollywood.com, "I do believe that miracles happen. It's a miracle that six years, almost seven years ago, I was digging ditches in Chicago and now I'm working with a two-time Academy Award winner and everyone is talking about the movie that we did together."