Sindika Dokolo, the husband of Isabel dos Santos, billionaire daughter of Angola's former president, has died, his family announced Friday.
Dokolo, a business tycoon and art collector, became entangled along with his wife in an anti-corruption investigation launched after her father, Jose Eduardo dos Santos, left office in 2017.
He died Thursday in Dubai according to a notice posted on Twitter by the family. It did not state the cause of death. Dokolo was 48.
"The Dokolo family, his wife, children, mother, brother and sisters have the deepest sorrow and immense sadness to announce the passing of Sindika Dokolo, which occurred on October 29, 2020 in Dubai," the tweet said.
On Thursday, Dos Santos posted on Instagram a picture of herself, Dokolo and a young boy, with the caption "My love."
Media reports in the neighbouring Democratic Republic of Congo, of which Dokolo was a citizen, said he had died in a diving accident.
DRCongo President Felix Tshisekedi expressed "his deep sorrow and sympathy" while Angolan leader Joao Lourenco tweeted his "deepest sympathy" to his predecessor on "the tragic death of his son-in-law".
Dokolo was a pro-democracy activist in his native country, where he openly opposed the rule of ex-president Joseph Kabila.
Elegant and youthful-looking, Dokolo married Dos Santos in 2002.
He was the son of Augustin Dokolo Sanu, a highly-influential Congolese banker during the era of dictator Mobutu Sese Seko, and Hanne, a Dane who still lives in Kinshasa.
Dokolo had interests in oil and diamond businesses in Angola and abroad but was also known for his extensive collection of contemporary African art.
Last year his foundation bought advertising on the NASDAQ electronic billboard in New York's Times Square to pitch his flagship project of returning to Africa artworks seized during colonial rule.
At the time of his death, Dokolo and dos Santos, 47, were under investigation by Angolan authorities who had frozen their bank accounts and business assets.
His wife, nicknamed "the princess" by many Angolans and described by Forbes as Africa's richest woman, is ex-president dos Santos's first daughter.
Dos Santos ruled Angola for 38 years -- an era widely associated with corruption and nepotism -- before stepping down in 2017.
Under his chosen successor, Joao Lourenco, prosecutors have begun probing the disappearance of billions of dollars in a country where a third of the population lives in poverty.
In August, the Supreme Court handed a five-year sentence to the ex-president's son, Jose Filomeno dos Santos, for fraud during the period he headed Angola's sovereign wealth fund, from 2013 to 2018.