JOHANNESBURG (AP) — Africa's reputed richest woman is a formal suspect in an investigation into mismanagement and the siphoning off of funds during her time with Angola's state-run oil company, the country's attorney general announced Wednesday.

The remarks by Helder Pitta Gros to reporters in the capital, Luanda, come days after a global investigation accused the billionaire Isabel dos Santos of murky dealings in the oil- and diamond-rich southern African nation whose people remain some of the poorest on Earth.

Wednesday's announcement is the latest sign that Angola's government under President Joao Lourenco is determined to pursue accountability after the International Consortium of Investigative Journalists accused dos Santos of using “unscrupulous deals” to build her fortune, estimated at $2 billion.

Dos Santos, daughter of Angola's former president, has denied any wrongdoing.

Already Angolan authorities this week have said they are reaching out to other countries for help in tackling the corruption that critics say has robbed millions of citizens of basic needs like quality health care.

And businesses are cutting ties. Portuguese bank EuroBic this week said it will stop doing business with companies and people linked to dos Santos, its main shareholder.

In a new statement Wednesday, the bank said dos Santos had decided to sell her stake in the institution.

The allegations in the investigation were based on more than 715,000 confidential financial and business records provided by the Platform to Protect Whistleblowers in Africa, an advocacy group based in Paris, as well as hundreds of interviews. The cache of documents is known as Luanda Leaks.

Jose Eduardo dos Santos, Isabel's father, ruled Angola for 38 years until 2017. Human rights groups have long accused him of stealing vast amounts of state money during his rule. Before stepping down, he appointed his daughter head of the state oil company, Sonangol.

Last December, a Luanda court froze Isabel dos Santos' major assets, which include banks and a telecom company. The government says it is trying to recover $1.1 billion it says the country is owed by dos Santos, her husband and a close associate of the couple.

Dos Santos has said the legal action against her is a “witch hunt” launched by officials who replaced her father.