Luanda - A group of Angolan lawyers has filed a landmark petition challenging veteran leader Eduardo dos Santos's nomination of his daughter, Africa's richest woman, as the head of the national oil company.
Isabel dos Santos was named head of troubled oil firm Sonangol in June in a move that some analysts see as the first sign of succession plans for Angola's iron-fisted ruler.
"The Supreme Court has accepted our suit and it's a very important step. It is the first time that the court will examine a decision of the president," said David Mendes, a spokesperson for 12 lawyers who filed the petition.
"The law stipulates that public officials cannot nominate or allow the nomination of family members," he told AFP on Tuesday.
Mendes said the court had given dos Santos and his daughter eight days to respond.
Nicknamed the "Princess", the 43-year-old Isabel has been ranked by Forbes magazine as the richest woman on the continent with a fortune of around $3bn.
She owns stakes in several companies in Angola and former colonial power Portugal, notably in the banking and telecommunications sectors.
Her new powerful role at Sonangol may position her for political office in a country ruled by her father for 37 years.
A member of the ruling MPLA party said dos Santos would not appear in court in person but would send a legal representative.
"The constitution of Angola is clear: the president does not have to personally explain actions taken during his term in court or in parliament," the member said, speaking on condition of anonymity.
Three years ago the president appointed his son Jose Filomeno dos Santos to chair the country's $5bn Sovereign Wealth Fund.
Sonangol has been mired in financial difficulties since the fall in global oil prices.
The southern African country's vast oil wealth has not trickled down to the masses and both dos Santos and his family are accused by critics of amassing huge wealth by siphoning off state funds.