Mark Shand, Prince Charles' brother-in-law and the brother of Camilla Parker Bowles, the Duchess of Cornwall, died Wednesday of head injuries from a fall outside a New York nightclub after a charity event.
Police said Shand, 62, left the Gramercy Park Hotel's Rose Bar to smoke a cigarette about 2:30 a.m. and fell backward as he tried to go back inside through a revolving door.
Officers said Shand was alert and complaining of head pain when medics arrived, according to the New York Daily News.
He was taken to Bellevue Hospital, where he died at 11:25 a.m.
The New York Post, citing unnamed sources, reported that Shand had been drinking and that he was taking blood-pressure medication that caused dizzy spells.
Initial news reports said he had fallen outside the Diamond Horseshoe, in the Paramount Hotel, where earlier he had attended a party following a benefit at Sotheby's.
Tuesday night, he had overseen the Faberge Big Egg Hunt auction for his charity,Elephant Family, which helps save endangered Asian elephants.
"The duchess, the Prince of Wales and all her family members are utterly devastated by this sudden and tragic loss," said a statement from Clarence House, the official residence of the Prince of Wales and Duchess of Cornwall. "Mark Shand was a man of extraordinary vitality, a tireless campaigner and conservationist whose incredible work through The Elephant Family and beyond remained his focus right up until his death."