Michael Madsen's cause of death has been confirmed days after his shock passing at the age of 67. The American actor, known for his roles in Kill Bill and Reservoir Dogs, was found "unresponsive" at his Malibu home on July 3 and was pronounced dead shortly after. Madsen's manager claimed he died from cardiac arrest. Madsen's cardiologist has now revealed he died of heart failure.

His doctor said heart failure will be listed as his cause of death, with heart disease and alcoholism named as contributing factors, claims NBC4 Los Angeles. It has also been reported that no autopsy will be conducted because Madsen's cardiologist will sign the death certificate. The Los Angeles Sheriff's Department has now closed the investigation and listed Madsen's death as from natural causes.

Madsen's representatives confirmed his death in a statement, saying; "In the last two years, Michael Madsen has been doing some incredible work with independent film, including upcoming feature films Resurrection Road, Concessions and Cookbook for Southern Housewives, and was really looking forward to this next chapter in his life."

His managers Susan Ferris and Ron Smith, and publicist Liz Rodriguez added: "Michael was also preparing to release a new book called Tears For My Father: Outlaw Thoughts and Poems, currently being edited. Michael Madsen was one of Hollywood's most iconic actors, who will be missed by many."

Madsen was best known for his collaborations with Oscar-winning director Quentin Tarantino, starring in Reservoir Dogs (1992), Kill Bill: Volume 2 (2004), The Hateful Eight (2015), and Once Upon a Time in Hollywood (2019).

Away from his work with the legendary director, Madsen also landed roles in Thelma & Louise, Donnie Brasco and Free Willy.

Madsen was reportedly trying to turn his life around up until the very end as he was believed to be sober before his death, despite a lengthy battle with alcoholism.

The actor fathered six children. In 1979, he had a daughter, Jessica, with Dana Mechling. During his four-year marriage to actress Jeannine Bisignano, he welcomed two sons, Christian and Max.

In 1996, Madsen tied the knot with actress DeAnna Morgan and they had three sons together, Luke, Kalvin and Hudson. Tragically, Hudson took his own life in January 2022.

Madsen is survived by his five children, his mother Elaine and his estranged wife DeAnna.