The Constitutional Court has rejected businessman Schabir Shaik's application to strike down parts of the National Prosecuting Authority (NPA) Act that he believed violated his right to silence - apparently after his lawyers appealed the constitutionality of the wrong sub-section of a law.

Justice Laurie Ackermann, in his last judgment before retiring, concluded it was "not in the interest of justice" to rule in Shaik's favour.

Shaik was in June 2002 summoned to the NPA under the Act to answer questions related to allegations of corruption in the government's arms acquisitions programme.

He appeared for the interview but then challenged its validity.

The proceeding was then postponed so that Shaik could take the matter to the Durban High Court.

The High Court agreed with Shaik that parts of the NPA, in particular section 28(6), violated his right to silence under section 35(1)(a) of the Constitution.

But it found that violation was reasonable and justifiable under section 36, the limitation of rights clause, because it played a crucial role in the fight against organised crime and corruption.

It also found that since the inquiry Shaik had been summoned to was neither judicial nor administrative, his demand for an independent arbiter was "ill-founded." The application was therefore dismissed with costs.

Shaik then asked the Constitutional Court for leave to appeal.

Argument at the hearing was limited to the constitutionality - or otherwise - of section 28(6) because of its alleged incompatibility with the right to a free trial, in particular with the rights of arrested and accused persons to remain silent.

Shaik was subsequently charged with a number of offences that he would have been questioned about at the section 28 hearing.

Ackermann said while the ruling would no longer benefit Shaik, as he was now an "accused" person, it was still of interest to persons who were - or would be - in a similar position.

Ackermann explained it was "constitutionally a serious matter for any court to declare legislation invalid."

It was therefore, he said "essential in order to ensure fairness to the state and other interested parties that the litigants identify accurately the statutory provisions they are attacking on constitutional grounds."

In this case, Ackermann said, it was not section 28(6) Shaik should have attacked, but section 28(8), as it was that sub-section that limited one's protection in terms of evidence compelled.

"Accordingly a proper justification enquiry under section 36(1) of the constitution could not and cannot now be conducted," Ackermann said.

Shaik's application was dismissed with all parties bearing their own costs.

Shaik is brother to Mo, Shamin (Chippy) and Yunis Shaik.

Mo, along with Mac Maharaj, is currently at the centre of the Bulelani Ngcuka "spy" inquiry, where he is represented by Yunis, a lawyer.

Shamin was the department of defence's chief acquisitions officer and played a central role in the controversial strategic defence programme, both within the department and as advisor to Cabinet.

He resigned after a disciplinary hearing found him guilty of illegally disclosing confidential information contained in the Auditor-General's draft report on the controversial arms deal late last year.

Schabir is chief executive of Nkobi Holdings, a black empowerment shareholder in African Defence Systems, a major benefactor of the arms deal as well as the department of transport's upgrade of the N3 highway and its introduction of the credit-card-sized driver's licences.

He is currently on trial for allegedly illegally possessing certain Cabinet documents related to the arms deal.

Shaik is also financial advisor to Deputy President Jacob Zuma.

With acknowledgements to Leon Engelbrecht, Sapa and Independent Online.