Conservationist and travel writer Mark Shand will be remembered for his dedication to protecting the endangered Asian elephant.
Prince Charles told Camilla to "down the hatch" as the pair pulled pints during a visit to an Essex pub today.
The Duchess of Cornwall came face to face with artwork of herself and the Prince of Wales at a traditional art fair in India.
Royal Editor Tim Ewart reports that the Duke and Duchess of Cambridge have been told of the death of Mark Shand, while on their royal tour of Australia.
From Canberra Tim Ewart said: "It's 7am in the morning here in Canberra. William and Kate have spent the night here with their son Prince George in an official residence. Their public engagements are about to start here in a couple of hours time.
"This tour is winding up and sadly, this event is going to cast a shadow over the last couple of days, of what has been a long and so far very successful and very happy tour.
"Both William and his brother Harry have become very close to the Duchess of Cornwall, despite all the family history and the background of the Diana affair.
"They were a close family and this statement from Clarene House, using the expression 'utterly devastated', applies to all the family.
"But royal duties here will carry on today, as they were going to before."
Mark Shand - the brother of the Duchess of Cornwall - was once married to the cousin of Jemima Khan. Following the news of his death Ms Khan tweeted:
RIP Mark Shand: Best man, godfather to my son & my cousin's ex "@imrankhanpti:Shocked to learn of death of 1 of my closest English friends"
Former Pakistani cricketer and politician Imran Khan has tweeted of his shock and sadness following the death of Mark Shand:
Shocked & saddened to learn of the death of one of my closest English friends',Mark Shand, in New York where he was raising funds 4 charity.
The Duchess of Cornwall is "utterly devastated" after her brother died from a serious head injury sustained in a fall in New York.
Mark Shand, 62, was taken to hospital on Tuesday night after reportedly slipping while lighting a cigarette and hitting his head on the pavement outside an after-party for a charity event.
He was in New York for an auction held at Sotheby's in aid of a charity for underprivileged children and the Elephant Family, which aims to save the endangered Asian elephant from extinction in the wild.
It was the finale for the month-long Big Egg Hunt NYC by Faberge, which saw egg sculptures, designed by well-known faces, sold to the highest bidder. The charity event raised $1.6 million (£950,000) for charity.
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."
The brother of the Duchess of Cornwall - Mark Shand - has died following a fall in New York, Clarence House has confirmed.
A statement reads: "It is with deep sadness that we have to confirm that The Duchess of Cornwall's brother, Mark Shand, has today passed away in New York.
"Mr Shand died in hospital as a result of a serious head injury which he sustained during a fall last night. The Duchess, The Prince of Wales and all her family members are utterly devastated by this sudden and tragic loss.
"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."
Mark Shand - the brother of the Duchess of Cornwall - has died after suffering a serious head injury following a fall in New York.
Mr Shand was a travel writer and the chairman of Elephant Family, which aims to save the endangered Asian elephant from extinction in the wild.
He had written several books about his travels, including 'Queen of the Elephants' and its accompanying BBC documentary.
The 62-year-old brother of the Duchess of Cornwall is in a New York hospital with a serious head injury after a fall in the city.
The Daily Mirror reports that Mr Shand had been attending a charity auction at Sotherby's in New York on the night of the fall. He was later at an after party for the event, when he stepped outside for a cigarette and slipped and hit his head on the pavement.
The brother of the Duchess of Cornwall - Mark Shand - has been taken to hospital with a serious head injury following a fall in New York.
A Clarence House spokesman said: "The Duchess of Cornwall's brother, Mark Shand, has been taken to a New York hospital after falling and sustaining a serious head injury.
The Duchess, her family and The Prince of Wales are clearly deeply concerned and are being kept closely informed."