Khalid Al Qasimi, the second son of Sheikh Mohammed Al Qasimi, was found dead in an apartment in the British capital on Monday. London police say his death is being treated as unexplained, the BBC reported.
The 39-year-old had forged a career for himself as a fashion designer. Clothes from his label, Qasimi, were shown at London Fashion Week.
The label said in a statement that he had "unexpectedly passed away" but no details of the circumstances of his death were released.
It added that "Khalid was praised for his tenacious yet sensitive exploration of social-political issues" and continued: "The design world has lost a great philosopher and artist".
Funeral prayers were held on Wednesday in the United Arab Emirates, where three days of national mourning were declared. Flags were flown at half-mast to mark the death.
His father, who has ruled Sharjah since 1972, expressed his sorrow in an Instagram post on Tuesday, saying his son was "in the care of God".
The President of the UAE and ruler of Abu Dhabi, Sheikh Khalifa bin Zayed Al Nahyan, offered his condolences to Sheikh Sultan and his family.
Khalid Al Qasimi's body was discovered by emergency services at an address in Knightbridge in central London. The cause of death was unknown after an autopsy on Tuesday gave inconclusive results, Scotland Yard said.
Al Qasimi moved to the UK when he was nine years old, where he attended Tonbridge School in Kent and University College London, where he studied French and Spanish.
He continued his education in architecture and fashion at the Central Saint Martins art college in London. Al Qasimi released his first collection in 2008.
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."
( With inputs from IANS )