Cape Town - Criminal prosecutions arising from the multi-agency arms deal investigations would not impact on the validity of the procurement contracts, the government's former corruption buster Willem Heath said on Thursday.

There was still a gap in the probe as the prosecuting authorities involved did not have the power to cancel deals on proof of wrongdoing.

"The arms deal contracts will still go ahead," he told Sapa.

Heath was reacting to ANC Chief Whip Tony Yengeni's arrest on charges of corruption, forgery and statutory perjury by the National Directorate of Public Prosecutions, one of the agencies involved in the investigation.

Heath - a former judge - was the head of the Special Investigating Unit (SIU), which was excluded from the investigation under controversial circumstances.

He has argued in the past that only the SIU had the power to rescind contracts if sufficient evidence was found of corruption.

President Thabo Mbeki announced in January this year that the SIU would be excluded from the probe, citing among other reasons a Constitutional Court decision that a judge cannot head a special investigating unit.

Heath 'excited' about prosecutions

Heath - who subsequently left the unit and resigned from the bench in June to become a private investigator and consultant - said he was excited that the authorities had begun prosecutions.

"Taking into account the allegations against him, it was very important that he (Yengeni) be prosecuted." However, a successful prosecution would depend on whether investigators had sufficient evidence to convict him.

He said he had read the charge sheet, but declined to comment on the strength of the case.

Yengeni - who resigned earlier on Thursday as Chief Whip of the ANC - is the first politician to be arrested since allegations of corruption in the deal were first made public in 1999.

The arms deal, announced in September 1999 at a cost then of R30 billion, includes the purchase of corvettes, fighter jets, helicopters and submarines.

However, with the rand continuing to lose its value the cost has already risen to R66 billion.

Yengeni faces a charge under the Corruption Act for receiving a R167 386 discount on his 4X4 vehicle from co-accused Michael Woerfel - the suspended head of the European Aeronautics Defence and Space Company (EADS) in South Africa.

EADS has a 33 percent stake in Reutech Radar Systems, a Stellenbosch-based company that secured a R220 million contract to provide radar for four corvettes.

Woerfel, who is out of the country, is expected to appear in court in Pretoria on October 10 on charges of corruption and forgery.

With acknowledgment to Sapa and News24.