It was unconstitutional for the National Prosecuting Authority (NPA) to summon an ex-intelligence official to testify in Jackie Selebi's trial without first informing the State Security Ministry, the ministry said in papers filed in the Constitutional Court in Johannesburg on Tuesday.

"Section 27(1) of the Intelligence Services Act provides that, subject to Section 10(3)(a), a former member may not disclose in any form or any manner any information or material to any other person, unless the director-general concerned has granted permission for the disclosure of such information or material," the document reads.

"The essence of the objection is that Mr [Barry] Gilder is not a compellable witness in terms of section 202 of the CPA [Criminal Procedure Act] and cannot testify on classified matters in the circumstances of this case unless the authorisation of the director-general is obtained as contemplated in section 27(1) of the IS [Intelligence Services] Act."

The state wants Gilder to testify about a 2005 draft intelligence report which contains a single paragraph about allegedly untoward payments Selebi was receiving from slain mining magnate Brett Kebble.

Attempts by the ministry - first in the High Court in Johannesburg and then in the Supreme Court of Appeal - to prevent Gilder from testifying, were turned down.

The ministry's argument is that Gilder's testimony could reveal sensitive information about State security.

But prosecutor Gerrie Nel argued in court last year that testimony wanted from Gilder would cover information already in the public domain, as several witnesses had already mentioned it in their testimony.

Selebi is facing a count of corruption and another of defeating the ends of justice in connection with some R1,2-million he allegedly received from Kebble, convicted drug trafficker Glenn Agliotti and ex-Hyundai boss Billy Rautenbach in return for favours.

He has pleaded not guilty to all charges.

His case is expected to resume on March 1.