A judicial inquiry alone could dissipate doubts hanging over President Thabo Mbeki and Auditor-General Shauket Fakie after claims of a watered-down final arms deal report, the Democratic Alliance said on Monday.

"Should the president fail to launch an investigation, he will send out a clear signal that his government is either unable or unwilling to deal decisively with the mounting allegations of corruption that continue to surround the arms deal," DA public accounts spokesperson Eddie Trent said in a statement.

"Only when these reports are properly and transparently investigated by a judicial commission will the cloud hanging over the executive and the AG be removed."

Trent said he had written and hand-delivered a letter addressed to Mbeki earlier in the day, asking him to appoint such a commission.

It should probe suggestions in media reports that potentially embarrassing claims of irregularities and fundamental flaws were removed from the AG's draft report into South Africa's multi-billion rand arms acquisition process under pressure from Mbeki and senior cabinet ministers.

"They (the reports) suggest that despite the AG's repeated claims to the contrary, he was indeed forced to bow to political pressure from the executive and in particular from President Mbeki," the DA statement said.

"The reports also allege that President Mbeki personally made rebuttals to every allegation of irregularities in the arms deal report."

If true, this would mean that the independence and credibility of the AG had been destroyed, the DA said.

"Furthermore, direct intervention by the president in what was supposed to be an independent report is a very serious allegation that needs to be fully dealt with as a matter of urgency."

Presidential spokesperson Bheki Khumalo said the DA request had not yet been received, and he could therefore not comment on the contents.

Any such request would be forwarded to the minister of justice, who would consider the motivation and make a recommendation to the president, he added.

Two national newspapers published extracts last Friday from a draft the AG had supplied to defence contractor Richard Young in terms of a court order.

Young said the draft showed that the final version, which concluded there were no grounds to suggest the government's contracting position was flawed, had excluded "absolutely fundamental and material findings" by investigators.

Among the changes was the removal of findings that there were "fundamental flaws" in the selection of BAE and Saab as suppliers of jet trainer and fighter aircraft.

The final report did not contain a record of objections from senior defence force members to buying more jet aircraft. It also excluded a finding that the late defence minister Joe Modise personally influenced the decision to opt for the more costly Hawk trainer rather than an Italian jet favoured by the South African Air Force.

Fakie maintained that due process was followed in the compilation of the final version, and stood by the report's contents.

Young is pursuing a R150-million damages claim against the government after his company lost out on a tender for corvette combat suites to a consortium with links to Durban businessman Schabir Shaik.

Shaik is on trial for fraud and corruption in the Durban High Court, partly related to the arms deal.

With acknowledgements to Sapa and Independent Online.