The integrity of the Seriti commission probing the arms deal has been questioned in a resignation letter penned by one of the commission's senior investigators, according to a report on Thursday.
Norman Moabi, a lawyer and former acting judge from Pretoria, alleges in his letter, which was leaked to Beeld newspaper, that the commission is not being transparent and is concealing an alternative or "second agenda".
Moabi says in the letter, addressed to judge Willie Seriti, that he is resigning because of interference and because he has lost faith in the commission's work.
"I joined the commission to serve with integrity, dignity and dedication to truth. I cannot, in all conscience, pretend to be blind to what is actually going on at the commission."
According to Moabi, Seriti rules the commission with an iron fist and facts are manipulated or withheld from commissioners.
Contributions from commissioners who do not pursue the "second agenda" are frequently ignored.
Beeld contacted Moabi, but he declined to comment.
Spokesperson for the Seriti commission, William Baloyi, said the commission would fulfil its mandate, as requested by President Jacob Zuma.
"Any other agenda referred to by Mr Moabi is a delusion."
Hearings were expected to start in March.
In October 2011, Zuma announced that Supreme Court of Appeal Judge Seriti would chair the three-man commission of inquiry, flanked by judges Hendrick Musi and Francis Legodi.
Initially, judge Willem van der Merwe — the same judge who acquitted Zuma on a rape charge — was appointed to assist Seriti, alongside Legodi.
But in December 2011, the Presidency said Van der Merwe had indicated he would not be able to serve on the commission for personal reasons.
Zuma then appointed Free State high court judge president Musi as Van der Merwe's replacement.
The deal, which was initially estimated to cost R43-billion, has dogged South Africa's politics since it was signed in 1999, after then Pan Africanist Congress MP Patricia de Lille raised allegations of corruption in Parliament.
Zuma himself was once charged with corruption after his financial adviser Schabir Shaik, who had a tender to supply part of the requirements, was found to have facilitated a bribe for him from a French arms company.
The charges against Zuma were later dropped.