If Schabir Shaik's claim that he loaned R1,2 million to Jacob Zuma during his financial crisis is true, the Deputy President will have to fork out about R2,4 million to repay him.

This is according to the state's key witness KMPG forensic director Johan van der Walt, who was tasked with compiling the 250-page report that the state hopes will prove Shaik solicited an annual bribe of R500 000 from French arms company Thomson-CSF to Zuma in return for his influence and protection from investigations into the arms deal.

However, defence advocate Francois van Zyl rejected Van der Walt's evidence on the grounds that the forensic director calculated the amount with interest on a daily basis instead of on a monthly basis as most banks do.

According to the defence, Shaik and Zuma signed a R2 million revolving loan agreement on May 16, 1999. The agreement was to run for five years.

Apparently an interest clause was added to the agreement after Zuma allegedly insisted on it. The interest to be paid is the prime rate plus two percent.

In his plea explanation, Shaik cites his Muslim faith as the reason why he could not accept the interest. He told Zuma the interest would be given to charity.

Van der Walt told the Durban High Court on Monday that if Zuma was to abide by the alleged loan agreement, his repayments of R2,4 million would be divided in half, with R1,2 million going to Shaik and the remainder to charity.

Earlier, the defence accused Van der Walt of being biased towards the state because he was paid to compile the report.

Van der Walt denied this, saying he conducted his investigations fairly and to the best of his ability and that other independent forensic auditors would have come to the same conclusions as he did.

Asked by Judge Hillary Squires about payment for his services, Van der Walt, trying to hide a smile, replied "somebody has to pay me I am not contributing to charity".

Although he did not reveal the exact amount he was paid, Van der Walt told the court his team were paid on an hourly basis.

Van der Walt spent 16 days in the witness box. He and his team investigated 50 000 documents relating to Shaik's business affairs.

After the court released him from the witness box on Monday, Van der Walt told journalists he was happy the investigations are over.

He said he is looking forward to working on his next case, but declined to divulge details.

He also looks forward to spending time with his family, who saw very little of him over the last two years.

His response to the defence's claim that he was biased was that he had done his job and he had a brilliant team to support him.

The state will introduce a new witness on Tuesday. It is expected that a former accountant at Shaik's Nkobi Holdings will take the stand.

With acknowledgements to Nivashni Nair and The Natal Witness.