Portuguese is investigating embezzlement claims against Isabel dos Santos, the billionaire daughter Angola's former president, the prosecutor general's office told AFP Friday.
The investigation comes after judicial authorities confirmed receipt of a complaint from Ana Gomes, a former Socialist lawmaker in the European parliament against Dos Santos.
Financial daily Jornal Economico reported last Friday that Gomes had passed to the Portuguese authorities "elements" she says cast doubt on the nature of funds which Dos Santos, nicknamed Africa's wealthiest woman, invested in former colonial power Portugal.
Last month, an Angolan court said it was freezing the assets of Dos Santos as part of an anti-graft campaign amid allegations of nepotism under the 38-year rule of rule of her father Jose Eduardo dos Santos, who left office in 2017.
According to the Angolan prosecutor general, Isabel dos Santos and her Congolese husband Sindika Dokolo are suspected of laundering a billion dollars worth of foreign currency during Dos Santos senior's 38-year rule, which ended in 2017.
Isabel dos Santos was appointed head of Angola's national oil company Sonangol in 2016, but was forced out by her father's successor President Joao Lourenco shortly after he came to power.
The corruption probe -- targeting several members of the former ruling family -- is looking at alleged irregularities involving Sonangol and also Sodiam, a national diamond-marketing firm.
Dos Santos, whom Forbes magazine named Africa's first woman billionaire in 2013, holds multimillion investments in Portugal's telecoms and financial sectors.
Last year, the Bank of Portugal revealed it would seek to follow up and "new facts" brought to light by the Angolan judicial authorities which could bring into question her eligibility to remain as a shareholder with Portuguese bank EuroBic.