The asset freeze pertaining to Isabel dos Santos, her husband Sindika Dokolo and associate Mario da Silva will not be treated as a corruption allegation because it is a civil matter related to debts owned to the state, spokesman Alvaro Joao said.

"The parties can resolve the case in a number of ways: recognising the debt to the state, and paying it, or taking it to the end of the case to let the courts decide," he said.

(Reporting by Victoria Waldersee; Writing by Noah Browning; editing by Louise Heavens)