The Crown Prince and second son of Dr Sheikh Sultan bin Mohammed Al Qasimi founded an eponymous fashion brand in 2016 and had shown collections at London and Paris Fashion weeks.
Three days of mourning have been announced in the United Arab emirate following the death of the “great philosopher and artist” in the UK.
Photographer Mariano Vivanco was among those paying tribute, calling him “my angel”.
His father posted on Instagram about the death, saying: “The arrival of the body of the deceased and prayers upon him will be announced.”
Khalid Al Qasimi studied architecture and fashion design at Central Saint Martins in London and was the brother of Sheikh Mohammed bin Sultan Al Qasimi, who died of a heroin overdose in 1999.
The ruler of the Emirate state of Sharjah found his eldest son dead on the floor of his quarters in the family’s £3 million English manor house in Sussex, an inquest heard.
A statement on the Qasimi website said: “Khalid was praised for his tenacious yet sensitive exploration of social-political issues, particularly pertaining to the Middle East and its sometimes strained relationship with the West, a subject very close to his heart and upbringing.
“His goal was to create ‘a world of beautifully crafted products infused with cultural, social and political undertones to inform and inspire’.
“The design world has lost a great philosopher and artist.”