Mohamed Al Fayed has died at the age of 94.
His family say he "passed away peacefully of old age" on Wednesday.
Sky News understands Al Fayed was buried after Friday prayers at London Central Mosque in Regent's Park.
The Egyptian-born businessman was best known as a former owner of the Harrods department store and Fulham football club in London.
Al Fayed's son, the film producer Dodi Fayed, and Princess Diana died on 31 August 1997 when their car crashed in a road tunnel in Paris as they tried to outrun paparazzi photographers on motorbikes.
The news of Al Fayed's passing comes just one day after the 26th anniversary of his son's death.
He fought a long campaign after their deaths, alleging the crash was not an accident and that it had been orchestrated by the British security services.
However, French police concluded it was an accident, caused in part by speeding and by the high alcohol level in driver Henri Paul's blood. A British police investigation concurred.
His family said in a statement: "Mrs Mohamed Al Fayed, her children and grandchildren wish to confirm that her beloved husband, their father and their grandfather, Mohamed, has passed away peacefully of old age on Wednesday 30 August, 2023.
"He enjoyed a long and fulfilled retirement surrounded by his loved ones. The family have asked for their privacy to be respected at this time."
He is survived by his second wife, Finnish former model Heidi Wathen, and their four children - Jasmine, Karim, Camilla and Omar.
Al Fayed sold Harrods to Qatar Holdings in May 2010.
Three years later, he also sold Fulham FC, to the US businessman Shahid Khan.
The club paid tribute to the businessman on Friday.
His successor as owner, Mr Khan, said: "On behalf of everyone at Fulham Football Club, I send my sincere condolences to the family and friends of Mohamed Al Fayed upon the news of his passing at age 94.
"The story of Fulham cannot be told without a chapter on the positive impact of Al Fayed as chairman.
"His legacy will be remembered for our promotion to the Premier League, a Europa League Final, and moments of magic by players and teams alike.
"I always enjoyed my time with Al Fayed, who was wise, colourful and committed to Fulham, and I am forever grateful for his trust in me to succeed him as chairman in 2013.
"I join our supporters around the world in celebrating the memory of Mohamed Al Fayed, whose legacy will always be at the heart of our tradition at Fulham Football Club."
Born in Alexandria in 1929, Al Fayed began his career selling fizzy drinks and then worked as a sewing machine salesman.
He built his family's fortune in real estate, shipping and construction, first in the Middle East and then in Europe.
After moving to London in the 1960s, Al Fayed soon became a friend of royals and high society and purchased high-profile businesses such as the Ritz Hotel in Paris in 1979 and Harrods in 1985.
He later bought Fulham in 1997 for £6.25m.
The Sunday Times Rich List 2021 reported Al Fayed and his family were worth around £1.7bn.
He became a friend of Princess Diana through his sponsorship of charities and events attended by Royal Family members.
He invited the princess, along with Prince William and Prince Harry, to holiday on his yacht in the summer of 1997.
Diana - who was divorced from Charles in 1992 - and Dodi were pictured together in St Tropez, sparking rumours of romance.
The billionaire's relationship with the Royal Family was recently depicted in season five of The Crown, where Al Fayed, played by Salim Daw, was seen getting to know Diana.
The sixth series of the show, set to be released this autumn, will cover Dodi and Diana's fatal crash.
Al Fayed was regularly shrouded in controversy.
He spent 10 years trying to prove Diana and his son Dodi were murdered.
Unsupported by any evidence, according to the inquest into Diana's death, he claimed that she was bearing Dodi's child and accused Prince Philip, the Queen's husband, of ordering Britain's security services to kill her to stop her from marrying a Muslim and having his baby.
His takeover of Harrods sparked one of Britain's most bitter business feuds, while in 1994 he caused a scandal with the disclosure that he had paid politicians to ask questions on his behalf in parliament.
He fell out with the British government over its refusal to grant him citizenship of the country that was his home for decades and often threatened to move to France, which gave him the Legion of Honour, its highest civilian award.
He has also been accused of sexual harassment by several former Harrods employees.
At Fulham, he erected a larger-than-life, sequined statue of Michael Jackson outside Craven Cottage even though the singer only attended one match.
When people complained, he said: "If some stupid fans don't understand or appreciate such a gift, they can go to hell."
He also installed a bronze memorial statue of Diana and Dodi dancing beneath the wings of an albatross at Harrods.
Even his name and date of birth were contentious.
He maintained he was born in 1933 but a British government inquiry into the Harrods takeover said 1929.
He also added the al to his name when he moved to the UK, leading the satirical magazine Private Eye to nickname him the "Phoney Pharaoh".