The Times today gives more detail: -
"Ms Dos Santos was put in charge of the struggling Sonangol in 2016 by the presidential decree of her father, José Eduardo dos Santos, whose regime became a byword for authoritarianism, corruption and nepotism. But when he retired as president in September 2017 she was quickly sacked.
Details of the family’s property portfolio in London highlight the issue of fortunes linked to allegedly corrupt regimes flowing into the city. Ms Dos Santos bought a house in Kensington, west London, for £8.65 million without a mortgage in 2007 via an anonymous company registered on the Isle of Man. The property website Zoopla estimates its present worth at £13.3 million."