Mark Shand, Prince Charles's brother-in-law and the brother of Camilla Parker Bowles, the Duchess of Cornwall, died Wednesday of head injuries suffered after slipping and falling outside a New York nightclub, the British media report.
Shand, 62, is believed to have hit his head on the pavement while smoking a cigarette outside the club. He had been attending and after party for following an auction for his charity, Elephant House, which helps save endangered elephants.
The accident occurred outside the Diamond Horseshoe Club, the Daily Mirror reports.
"The duchess, the Prince of Wales and all her family members are utterly devastated by this sudden and tragic loss," Clarence House said, according to the BBC.
Clarence House is the official residence of the Prince of Wales and Duchess of Cornwall.
The conservationist and travel writer had attended the charity auction at Sotheby's in New York.