The Angolan government has vowed to use “all possible means” to force the return of Isabel dos Santos following the Luanda Leaks investigation into how the ex-president’s daughter accrued her $2bn fortune.

Angola’s prosecutor general, Hélder Pitra Grós, said on Angolan public radio on Monday that the country would use “all possible means and activate international mechanisms to bring Dos Santos back to the country”.

Dos Santos left Angola in 2018 after her father stepped down as president. She has denied any wrongdoing.

In a string of tweets after the Guardian and partners revealed the story behind her fortune on Sunday, she denounced the Luanda Leaks investigation – based on 715,000 files from her business empire – claiming it was part of a concerted campaign by the Angolan government to discredit her.

“The ICIJ report is based on many fake documents and false information, it is a coordinated political attack in coordinations with the ‘Angolan Government’. 715 thousand documents read? Who believes that? #icij #lies,” she tweeted, referring to the International Consortium of Investigative Journalists, of which the Guardian is a partner.

Dos Santos says her wealth is the result of hard work and business acumen rather than state funds. “I build companies and enterprises, I invest and create jobs. This where my wealth comes from: BUSINESSES,” she tweeted last night.”

At the UK-Africa Investment Summit in London on Monday, attended by 21 African countries, a member of the Angolan delegation denied Dos Santos’s descriptions of the government’s actions as a “witch-hunt”.