Former Angolan President José Eduardo dos Santos has held a surprise press briefing in the capital, Luanda, to defend himself against his successor's allegation that he left the country broke when he stepped down last year.

“I did not leave the state coffers empty. In September 2017 at the time of the changeover of presidents, I left $15bn (£11bn) in the National Reserve Bank (BNA),” he said.

The 76-year-old, who ruled the southern African nation for 38 years, did not take questions from reporters.

His daughter, Isabel dos Santos, who is Africa's richest woman, tweeted about the event.

She alluded to the country's strained finances blaming President João Lourenço for the situation.

Mr Lourenço had told Portugal's weekly Expresso newspaper on Saturday that he found the country’s coffers empty when he took over, the East African newspaper reports.

When asked if he would disclose his own assets, President Lourenço told the paper he had no need to do so as he was not wealthy.

“I am not a millionaire or a billionaire,” he said.

Since coming to office, the 64-year-old has also targeted members of his predecessor's family in an anti-corruption crackdown.

He fired Ms dos Santos last year from heading the state oil company Sonagol. She has denied any wrong-doing but prosecutors have summoned her to answer questions about her 17 months running the firm.

Her brother, José Filomeno dos Santos, was detained in September on suspicion of money-laundering, embezzlement of public funds and fraud. He has not commented on the allegations.