South Africa's main opposition party said it had asked the High Court to force President Jacob Zuma to disclose how much the state has spent on legal fees to fight corruption allegations against him.

Democratic Alliance (DA) Federal Council Chairperson James Selfe said on Sunday in a statement the opposition party had asked the court to direct the president to write to parliament within five days confirming the total amount spent.

The DA walked out of a parliamentary session addressed by Zuma on November 2, in protest over the potential cost to the public purse of his legal fees. Zuma had failed to answer a question about how much had been spent since May 1, 2009, to defend 783 corruption charges against him that were dropped by the National Prosecuting Authority (NPA) before he ran for the presidency.

"By avoiding the question, the DA believes that both the president and the Deputy Speaker, Lechesa Tsenoli, presiding at the time who allowed President Zuma to avoid the question, acted unlawfully and unconstitutionally," Selfe said.

"Given that the taxpayer has most likely footed the bill for the president's legal costs, the full amount spent should be revealed, in the public interest."

South Africa's High Court reinstated the 783 charges last year and the Supreme Court upheld that decision in October, rejecting an appeal by Zuma. The 75-year-old president is still trying to prevent the NPA from filing the charges.