The Democratic Alliance (DA) has again asked the High Court in Pretoria to review the decision to drop charges against President Jacob Zuma, arguing that it was irrational and unlawful.

In a statement on Sunday, the party said it submitted responding affidavits to the court on Friday.

The National Director of Public Prosecutions and Zuma's legal team submitted affidavits in April, during in argument opposing the DA application for a review.

"The prosecution of Mr Zuma was a matter of extraordinary public and constitutional importance," the party said.

"The decision not to prosecute has seriously dented public confidence in the independence of the criminal justice system."

Early in April, the DA filed an application for a judicial review of the decision to withdraw fraud, corruption, racketeering and money laundering charges against Zuma.

At the time, party leader Helen Zille said the National Prosecuting Authority's (NPA's) decision was not only unlawful and unconstitutional, but gave Zuma a legally unencumbered run to the presidency.

In its latest responding affidavits, the DA said it wanted produced for scrutiny the documentation the NPA relied on in its decisions on the prosecution of Zuma.

"There is nothing uniquely confidential about Mr Zuma's representations," the DA said on Sunday.

"That the NPA will not produce these records leaves serious questions as to what they contain, and whether they justify the decision to drop the charges.

"Failure to produce this record, in our view, leaves no option but to subject the decision to judicial review," it said.

In the NPA's affidavits filed in April, NPA head Mokotedi Mpshe contended the DA's request for judicial review would "lay bare the President's highly sensitive personal record".

The DA, however, contends that "Zuma should not escape prosecution just because he is politically powerful".