Angolan prosecutors have vowed to use "all possible" means to bring back Isabel dos Santos, the former president's billionaire daughter after thousands of leaked documents brought new allegations she siphoned off hundreds of millions in public money.

Dubbed Africa's richest woman, dos Santos is accused of using her father's backing to plunder state funds from the oil-rich but impoverished southern African country and — with the help of Western consulting firms — move the money offshore.

She stopped living in Angola after her authoritarian father Jose Eduardo dos Santos, who ruled the country for nearly 40 years, stepped down in 2017 for his anointed successor Joao Lourenco.

She now spends her time between London and Dubai.

"We will use all possible means and activate international mechanisms to bring Isabel dos Santos back to the country." prosecutor general Helder Pitra Gros told public radio.

The 46-year-old dos Santos is already being investigated as part of an anti-graft campaign launched by Lourenco, who has vowed to root out corruption.

Prosecutors last month froze the bank accounts and holdings owned by the businesswoman and her Congolese husband Sindika Dokolo, a move dos Santos described as motivated by a groundless political vendetta.

The prosecutor general said "it was quite a coincidence that she received our (investigation) notification during the day and at night she left the country."

"We have asked for international support from Portugal, Dubai and other countries," he said.

The prosecutor's remarks came after a trove of 715,000 files dubbed the "Luanda Leaks" was released on Sunday revealed how the eldest daughter of the former president of allegedly moved the vast sums into overseas assets.

The award-winning New York-based International Consortium of Investigative Journalists (ICIJ) behind the release alleged the international system has allowed powerful individuals like her to move assets around the world, without questions.

"Based on a trove of more than 715,000 files, our investigation highlights a broken international regulatory system that allows professional services firms to serve the powerful with almost no questions asked." the ICIJ wrote.

The group said its team of 120 reporters in 20 countries was able to trace "how an army of Western financial firms, lawyers, accountants, government officials and management companies helped (dos Santos and Dokolo) hide assets from tax authorities."

Dos Santos took to Twitter to refute the claims, launching a salvo of around 30 tweets in Portuguese and English, accusing journalists involved in the investigation of telling "lies".

"My fortune is built on my character, my intelligence, education, capacity for work, perseverance." she wrote.