The costume maker passed away in his sleep earlier this week (begs04Jun12) at the age of 79, Collins confirms to the New York Times.
Miller designed more than 3,000 costumes for the 1980s drama and won an Emmy Award in 1984 for his work on the show. He once famously declared, "I never want to see them wearing the same outfit twice."
The designer also worked on programmes including Charlie's Angels and Hart to Hart, and privately dressed stars such as Dame Elizabeth Taylor and Sophia Loren.
His cause of death was unknown as WENN went to press. Miller was previously diagnosed with lung cancer in 2006, and announced his retirement from the industry last year (11).