An Angolan court has ordered the seizure of the assets and bank accounts of the billionaire daughter of ex-President José Eduardo dos Santos.
The seizure appears to be part of an anti-corruption drive by the current government in oil-rich Angola.
The administration of President Joao Lourenço is seeking to recover $1bn (£760m) it says it is owed by Isabel dos Santos and her associates.
She has repeatedly denied wrongdoing during her father's term in office.
Often described as Africa's richest woman, Ms Dos Santos is estimated by Forbes magazine to have a fortune of $2.2bn.
The 46-year-old lives abroad, saying she moved from Angola because her life had been threatened.
She runs a huge business empire with stakes in companies in Angola and Portugal, where she has shares in cable television firm Nos SGPS.
The court ordered the freezing of Ms Dos Santos' Angolan bank accounts and the seizure of her stake in local companies, including telecoms giant Unitel and bank Fomento de Angola (BFA), the state-owned news agency reported.
In a statement, she said she condemned what she described as a "politically motivated attack" against her.
"I discovered that a trial had been held in total secrecy in Angola and the decision taken to issue a freezing order on my assets. There were no lawyers from my side present, nor the directors of my companies. We were only informed about it after the decision had been taken behind our backs.
"I have spent the last 24 hours trying to give assurances to my staff and all the families affected by this order that we must not give in. I will use all the instruments of Angolan and international law at my disposal to fight this order and ensure the truth comes out."
Ms Dos Santos gained a high public profile in 2016, when her father controversially appointed her as the head of Angola's state-owned oil firm Sonangol.
She was sacked from the post in 2017 by Mr Lourenço, her father's handpicked successor.
Her brother, José Filomeno dos Santos, is on trial in Angola on charges of corruption.
The prosecution alleges that he and his co-accused helped spirit $500m out of the country during his time as head of Angola's Sovereign Wealth Fund. They have pleaded not guilty.
Serious about reforms?
By Andrew Harding, BBC Africa correspondent
The court order was read out on state television - a powerful gesture in a country where, for decades, the Dos Santos family had seemed untouchable.
Now, the fate of the vast business empire of Isabel dos Santos, the eldest daughter of the former president, is in doubt.
Two years ago, Mr Dos Santos stepped down after 38 years in power. And to the surprise of many, his successor turned against the family, promising a major crackdown on corruption.
Since then, billions of dollars in stolen assets have been recovered from abroad.
Angolans are waiting to see if one alleged kleptocracy will simply be replaced by another or whether, as many hope, this vast oil-rich but impoverished nation is now serious about reforms and justice.