The Scorpions investigation unit has vowed to deal with high-ranking people who use their political connections to commit criminal acts.

A number of high-profile arrests were expected "very soon", Scorpions spokesperson Sipho Ngwema told the Sunday Times yesterday.

It is understood that the anticipated arrests relate to the government's multi-billion rand arms deal.

The unit claims that "comrade criminals" - a reference to members of the ANC, are running a disinformation campaign to malign its boss, National Director of Public Prosecutions, Bulelani Ngcuka.

In recent months journalists have been swamped with sensational rumours against Ngcuka, none of which could be substantiated.

It was reported last week that Ngcuka was about to resign to join mining house De Beers, something which he has denied.

It was also alleged that Ngcuka's wife, Phumzile Mlambo-Ngcuka, the Minerals and Energy Minister, would negotiate concessions for the company.

Ngcuka has dismissed these rumours as "scurrilous", saying they were an attempt to divert the course of investigations into the arms deal.

Ngwema said the unit had been "aware of the allegations for some time".

"Most of the people behind these allegations have committed criminal offences. They are attempting to discredit the unit so that the allegations against them will fall away. This will not happen. There will be arrests very soon," said Ngwema.

"They have no political mandate and are serving their own interests. In the same way, their criminal acts were for personal gain," he said.

Ngwema said Ngcuka would not raise the issue with his political bosses or in the ANC.

"At this stage, we have the capacity to deal with the situation," he said.

In February former ANC chief whip Tony Yengeni was convicted of fraud and corruption in connection with the arms deal.

Former Defence Minister Joe Modise was under investigation by the Scorpions at the time of his death, and Deputy President Jacob Zuma, along with his financial advisor Schabir Shaik are currently under investigation in connection with the arms deal.

Shaik is disputing the validity of a summons forcing him to answer the questions about an allegation that Zuma tried to get a R500 000 bribe from a company involved in the arms deal. Both Zuma and Shaik have strongly denied the bribery allegations.

The allegations, made in court papers that became public in December last year, detail an alleged arrangement for the French defence group Thales to pay Zuma R500 000 a year in exchange for "protection" from a government investigation, as well as continued support that could benefit the company.

In the Durban High Court on Friday, Shaik's counsel, Nirmal Singh, questioned whether it was legally proper for suspects and accused people to be summonsed to testify in cases in which they could be incriminated.

Singh argued that doing so would violate an accused's constitutional right to a fair trial.

The state's submission is that any person maybe summonsed under Section 28 (6) of the National Prosecuting Authority Act, the legislation in terms of which Shaik was ordered to testify.

Marumo Moerane SC, who is representing Ngcuka, said that Shaik was a suspect and not an accused in this case. Shaik therefore did not enjoy the right to remain silent, he argued.

On Friday Judge Ron McLaren reserved judgement in the matter.

Shaik was arrested in November 2001 for allegedly stealing documents relating to a confidential Cabinet meeting at which the arms deal was discussed.

At the time he was a director of Nkobi Holdings, African Defence Systems and Thomson - all alleged to have benefited from the arms deal. He is out on bail of R1 000.

Shaik also showered former Transport Minister Mac Maharaj and his wife with gifts and payments worth more than R500 000.

Maharaj was still in the Cabinet at the time that he received most of the gifts and money.

Shaik is the chief executive of Nkobi investments, part of the N3 Toll Road Consortium, which was awarded the R2,5-billion tender to upgrade the national road between Johannesburg and Durban by the Department of Transport while Maharaj was the minister.

With acknowledgements to Ranjeni Munusamy, Ilse Fredricks and the Sunday Times.