Britain has imposed sanctions on Angola’s Isabel dos Santos, a billionaire businesswoman and daughter of a former president, as part of a crackdown on money laundering promised by the new Labour government.

The measures also impact an exiled Ukrainian oligarch, Dmytro Firtash, and Aivars Lembergs, one of Latvia’s richest men.

Describing the three tycoons as “notorious kleptocrats”, it has frozen their UK assets and implemented a travel ban on them.

Britain’s foreign secretary said they “selfishly deprive their fellow citizens of much-needed funding for education, healthcare and infrastructure – for their own enrichment”.

London says dos Santos abused her position at Angolan state oil company, Sonangol and telecoms company, Unitel, to embezzle at least $440 million.

Dos Santos, whose late father, Jose Eduardo dos Santos ruled Angola for 38 years – claims to be Africa’s first female billionaire.

Her downfall began soon, soon after a new president came to power in 2017, and in the past few years she has faced numerous corruption charges in multiple countries.

She has denied the allegations saying she is the target of a political vendetta.

Dos Santos has described the British sanctions as “incorrect and unjustified” adding that she was not given an opportunity to defend herself and will appeal the decision.