Mark Shand - the brother of the Duchess of Cornwall - was the chairman of Elephant Family, which aims to save the endangered Asian elephant from extinction in the wild.
In a statement, the charity said it had "lost the head of our family".
The statement on the charity's website reads: "Today we have lost the head of our family. Mark Shand was a true force for conservation.
"He was both a legend and inspiration and above all our great friend. We ask at this time that people’s thoughts are with his loved ones. We will miss him always."
More top news
ITV News can reveal the number of potential buyers for Tata's steel business in the UK is more than double the previously known total.
Officers combined hip-hop with bagpipes and traditional ceilidh dancing in the hilarious clip.
A paranoid schizophrenic with ovarian cancer will undergo a hysterectomy after a judge ruled she could not decide on treatment herself.