The New National Party backed calls on Wednesday by other opposition parties for the probe into South Africa's multi-billion rand arms deal to be re-opened.

"The time has come for government to answer the unanswered questions related to the arms deal," NNP media director Adriaan van Jaarsveld said in a statement.

"The perception exists that transparency was sacrificed in getting to the final report on the investigation into the arms deal.

"Everything possible must be done to answer to this perception. It is taxpayers' money that is spent on these arms and they have the right to be convinced that everything was above board," he said.

The NNP supported the plan for Parliament's public accounts committee (Scopa) to revisit the investigation.

It was the responsibility of all politicians to ensure that citizens had confidence in organs of state.

"Now is the time to put the controversy behind us and get clear answers to the serious questions that still linger," Van Jaarsveld said.

On Tuesday, Democratic Alliance leader Tony Leon said the DA would ask Parliament to urgently set up an ad hoc multiparty committee to investigate the deal.

Parliament had the power to question everyone involved in the controversial deal, he told the Cape Town Press Club.

"It is very late in the day, but Parliament can still redeem itself.

"Having being marginalised and deligitimised throughout the arms deal fiasco, surely Parliament can finally reassert itself."

Leon suggested a new committee investigate the deal as Scopa, which had called for the initial probe, had been sidelined and weakened.

Auditor General Shauket Fakie -- whose office, with the Public Protector and National Directorate of Public Prosecutions, investigated the deal --has been accused of allowing the probe's final report to be edited to omit vital information.

But, in a statement earlier this week, the AG dismissed the allegations, saying the draft and final reports had not been closely studied and compared.

"This irresponsible behaviour has led to inaccuracies being published, and a biased, unfair cloud of suspicion being created against the Auditor-General and his office."

Fakie said he was prepared to defend himself in court as "this is the proper forum for these issues to be aired".

With acknowledgement to Sapa.