Last month, Angola named dos Santos as a formal suspect over allegations of mismanagement and misappropriation of funds during her time as chairwoman of state oil company Sonangol.

Portugal's public prosecutor said last week it had ordered the seizure of her Portuguese bank accounts after the country's market watchdog said it had launched inquiries into firms where she holds stakes.

"The lady is not our shareholder. Our shareholder is Amorim Energia, a fully family-controlled company. We are quite distant from that discussion, thank God" CEO Carlos Gomes da Silva told Reuters on the sidelines of an investor presentation on Tuesday.

In a partnership with Sonangol and Portugal's wealthy Amorim family, dos Santos bought a third of Galp in 2005 using large amounts of commercial debt.

Da Silva said Galp had not been affected by freezes put on dos Santos's bank accounts or by probes into her partnerships with Portuguese companies.

He added that there had been no sign that Sonangol would take full control of dos Santos's stake, and said there were no plans for Galp to buy stakes in the Angolan energy firm in a partial privatisation planned to take place within two years.

Dos Santos told Reuters in an interview last month that efforts to split the joint stake she shared with Sonangol in Galp Energia had been scuppered by a freeze on her assets by Angola at the end of 2019.

Dos Santos, the daughter of former Angolan president Jose Eduardo dos Santos who ended his nearly four-decade grip on power in 2017, has repeatedly denied any wrongdoing.

Buoyed by high oil prices in the last decade, Angolan businesses bought up sizeable assets in former colonial master Portugal, with dos Santos acquiring stakes in several Portuguese firms.

By Noah Browning