A spokesman for the Metropolitan Police said that they were called to the Four Seasons Hotel in London's Canary Wharf about "reports of an unexplained death of a man in his 60s. This is being treated as non-suspicious at this stage".
Gest's friend Imad Handi confirmed the news in a statement, reported Variety.
"David was truly larger than life. He was not just a huge talent and a dear friend but a showbiz icon. I know he will be missed by millions of fans around the world, and particularly in Britain, who came to love his charm and blistering one-liners," the statement said.
Gest was married to Minnelli from 2002 to 2003, but they didn't officially divorce until 2007. He sued her for USD 10 million after they separated, claiming that she had physically assaulted him during their relationship.
Like Minnelli, he was a friend of Michael Jackson and produced a 2011 documentary on the King of Pop, "Michael Jackson: The Life of an Icon," following his death. He also produced a TV musical special - then touted as the highest rated in history - 2001's "Michael Jackson: 30th Anniversary Celebration" the last reunion between Jackson and his brothers.