South Africa's main opposition Democratic Alliance (DA) says it has requested the president to provide details of the home loan he took to in respect of the infamous Nkandla upgrade refund.

The DA said it had written to President Jacob Zuma requesting him to provide proof to the National Assembly of his R7.8 million loan with VBS Mutual Bank. The details requested include:

The loan agreement, including the details of the loan repayment; and any other relevant supporting documentation.

''President Zuma must finally come to the realisation that he is not above the law, and that he must face the criminal charges that are brought against him. We urge the NPA to operate independently, and without fear and favour, and make a decision without delay,'' a DA statement released on Wednesday read.

The DA also expressed worry at the news that almost 1000 days after DA's corruption charges against Zuma, the National Prosecuting Authority (NPA) was still undecided on its next steps.

The charges relate to the misapplication of funds by Zuma in the upgrade of his private Nkandla residence. According to the DA, it was extremely concerned that the NPA was dragging its feet on the way forward.

''It is extremely concerning that the NPA - an independent body - is dragging its feet in making a decision in this matter. We cannot afford for this matter to be dragged out,'' the DA statement added.

The DA disclosed that the Minister of Justice and Correctional Services in a response to their query on the issue stated that "The National Prosecuting Authority is still considering the matter, no decision has been taken whether or not to prosecute any person(s) in relation to the matter".