The defence ministry is refusing to hand over a report about the Swiss secret services' links to South Africa's former apartheid regime. The Federal Prosecutor's Office wants the documents as part of an inquiry into the former head of the secret service, Peter Regli.
"We will not hand over these documents because they are classified and secret," defence ministry spokesman, Oswald Sigg, told swissinfo. "We will not have these documents being used in a process which is public."
The Prosecutor's Office is probing allegations that Regli was involved in the criminal activities of Wouter Basson, South Africa's director of a covert chemical weapons programme during the apartheid era.
The allegations were made in a Pretoria court by Basson, who is on trial for murder, attempted murder and fraud. He has been dubbed "Dr Death" by the South African media for leading the apartheid regime's secret chemical weapons programme, known as "Coast".
The defence ministry said that prosecutors were free to read its internal report on relations between the two countries' secret services, but that it would not release a copy into the public domain.
The ministry added that it had the power to veto any information from the report that prosecutors might want to use in court. "They can use information from this report which we will select," Sigg said.
Sigg would not specify which facts would be barred from the public arena, and dismissed the idea that the defence ministry was trying to hide information.
"I don't think this is a cover-up because the prosecutors have the possibility to access and read all the information," Sigg said.
In his testimony last month, Basson claimed Regli had helped him obtain 500kgs of Mandrax, an illegal drug, from Russia in 1992.
Basson also implicated Jürg Jacomet, a freelance agent of Switzerland's secret service, Jürg Jacomet.
Two years ago, a Swiss parliamentary inquiry investigated allegations of collaboration with the South African secret service. But the commission leading the inquiry accepted Regli's explanations in 1999 that his contacts were "purely of an informative nature".
Two weeks ago, the Swiss defence ministry decided to launch an internal investigation into Basson's allegations. The inquiry will also try to establish whether any documents relating to Swiss-South African intelligence cooperation might be missing.
An interim report, due on October 31, will either close the affair or lead to an external and more thorough investigation "if the slightest suspicion is brought to light," Sigg said.
Swiss media reported that the document in question was prepared by Regli himself, although Sigg refused to confirm this.