Isabel dos Santos issued the following statement on Thursday after being formally named as a suspect by the Angolan attorney general in connection with a criminal inquiry into embezzlement at the state oil company Sonangol.

The allegations which have been made against me over the last few days are extremely misleading and untrue. We will seek to clarify our position in relation to the latest accusations. This is a very concentrated, orchestrated and well-coordinated political attack, ahead of elections in Angola next year. These claims are being placed at a time of economic instability in Angola. It is an attempt to neutralise me and to discredit the legacy of President dos Santos and his family. No one should be taken in by these diversionary tactics. Stolen documents have been leaked selectively to give a false impression of my business activities. I am a private businesswoman who has spent 20 years building successful companies from the ground up, creating over 20,000 jobs and generating huge tax revenue for Angola. Last year my businesses paid over $100m in tax. I have always operated within the law and all my commercial transactions have been approved by lawyers, banks, auditors and regulators. Sadly, the rule of law has been undermined in Angola where the courts are subject to political pressure. However, I am ready to fight through the international courts to defend my good name. I have engaged lawyers to take action against inaccurate and defamatory reports. We deny all the latest allegations being made by Angolan authorities.

Previously, responding to the Luanda Leaks investigation, Isabel dos Santos and her husband, Sindika Dokolo, denied all allegations of wrongdoing.

In an interview with BBC News and a letter from her lawyers, Dos Santos denied the suggestion that she owed her business success to nepotistic support from her father, a former president of Angola, and said corruption accusations were intended to smear her reputation.

Angola’s attorney general is investigating allegations of mismanagement during Dos Santos’s time as head of the state oil company, Sonangol, and in December a civil court froze her assets, accusing her of having enriched herself at the expense of the state.

Q&A What is the Luanda Leaks investigation? Show The Luanda Leaks project is based on a trove of 715,000 emails, charts, contracts, audits and accounts detailing the business operations of Isabel dos Santos, the daughter of the former president of Angola. The files were initially obtained by the anti-corruption charity Platform to Protect Whistleblowers in Africa (PPLAAF), which shared them with the International Consortium of Investigative Journalists (ICIJ). The documents, which cover a period between 1980 and 2018, have been reviewed by more than 120 journalists from 37 media outlets, including the Guardian, the BBC and the Portuguese newspaper Expresso.

Her lawyers said: “It is obvious that our client is the subject of a highly coordinated attack on both her reputation and business, an attack which originates from the Angolan authorities.”

She told the BBC her accusers in the Angolan government were pursuing her as part of a “witch-hunt” intended to discredit her and her father, saying she was a private businesswoman who had developed her holdings over 20 years.

Her businesses were commercially successful in their own right, she said, and did not require presidential backing. She said of her TV distribution business: “You’re not going to tell me that people went and bought the box to watch satellite television because my father is the president. That’s utterly rubbish.”

Sonangol

Dos Santos said that by 2015 it was widely known that Sonangol was close to bankruptcy, with $20bn of debt and a collapse in the price of oil. The government therefore established a commission to restructure the country’s oil sector, which invited Dos Santos’s company Wise Intelligence Solutions to manage the project.

Dos Santos said that despite initially refusing several times, she subsequently accepted an invitation to chair Sonangol for the restructure.

The oil company’s board of directors then approved the transfer of Wise’s contract to the Dubai company Ironsea Consulting, later renamed Matter Business Solutions, “a consulting firm with capabilities and knowledge of the Angolan market”. Dos Santos said neither she nor her husband owned Matter, and that she did not vote on that decision so as to avoid any conflict of interest.

She said consultancy costs for the restructure project were $115m, adding that this was far lower than consultancy costs incurred by her predecessors. In response to questions about the series of invoices settled in the final days of her leadership, her lawyers said that by June 2017 a large unsettled consultancy bill had built up.

“In order to settle the outstanding invoices, a number of payments began to occur between June and November 2017, with the final payment occurring by 15 November 2017,” they said. “Instruction for payment of $38m a few days prior to the board’s dismissal related to invoices received, for services that had already been provided and delivered by consultants in accordance with contract.”

De Grisogono

In an interview with Radio France Internationale, Dokolo described the Angolan government’s attempt to seize his assets as “armageddon”. “They want to blame us for all the corruption and bankruptcy in Angola,” he said.

A letter from Dokolo’s lawyers said accusations of nepotism and corruption against him “simply parrot the politically motivated allegations from the current Angolan government”. They said he had invested in De Grisogono in 2012 after three years of negotiation, in partnership with the Angolan state diamond company Sodiam.

In response to claims Sodiam’s investment was funded by a high-interest loan from a bank part-owned by Dos Santos, the lawyers said a rate of 9% was “market-standard”. They accepted that Dokolo had received a “remuneration fee” of $5m for helping to acquire and structure De Grisogono. They said both Dokolo and Sodiam had invested equal amounts of $115m in De Grisogono.

The Angolan government has also accused Dokolo of benefiting from diamond sales at below market rates. Dokolo claims that in fact Sodiam was paid an above market rate of an additional 5% as goodwill in exchange for the diamonds.

The lawyers added that De Grisogono’s performance had in fact improved from 2012 to 2017 as part of “an extensive business turnaround process”, and that events at the Cannes film festival were part of a marketing campaign approved by the company’s board.

Isabel dos Santos told BBC News she was not a shareholder of De Grisogono.

Luanda masterplan and Marginal da Corimba

Dos Santos’s lawyers say her company Urbinveste, working with a team of international contractors, helped design the Luanda masterplan for Angola’s capital, which won an architectural award. They say her company consulted widely, with more than 40 meetings, presentations, public consultations and seminars.

Urbinveste also envisioned the concept of the related Marginal da Corimba project, paying for its initial design stages, to ameliorate Luanda’s traffic congestion.

The lawyers said the project had “minimal environmental and social impact, notably by there being no need of any expropriations, and no need to evict or relocate any residents or any communities” by virtue of all the land being reclaimed from the sea.

Her lawyers said “there were never any evictions related” to the Marginal project, and said allegations of overcharging were “false and unfounded”. They stressed the Luanda development project her company was involved in was ultimately abrogated by João Lourenço, José Eduardo dos Santos’s successor as president.

Galp

Lawyers for Dokolo deny allegations that a stake in the Portuguese energy company Galp was acquired in a preferential deal with the Angolan state, and that a loan financing that stake is in default.

They say that Dokolo and the Portuguese businessman Américo Amorim first sought to acquire a stake in Galp in 2005, and entered discussions about a possible joint investment with Sonangol.

They say Dokolo’s company Exem Energy BV committed to invest €75m, corresponding to the size of the 40% share of the stake in Galp held through a company called Esperaza.

They said that in the summer of 2017 Sonangol asked Exem to repay its loan in the Angolan kwanza currency to help offset a liquidity crisis, and that Exem accordingly transferred the money in October 2017.