The refusal by SA's security agencies to release classified files to the Hefer commission is to be challenged today.

At the request of former transport minister Mac Maharaj and Mo Shaik the commission asked the security agencies to provide documentation that would presumably prove that national prosecutions chief Bulelani Ngcuka was an apartheid spy.

However, the intelligence department, safety and security department, the defence department, the South African Police Service, the South African Secret Service and the National Intelligence Agency are opposed to providing documentation, saying that to do so would be illegal and would threaten national security.

Anyone who requires such information would have to apply to the directors-general of the government departments, and they reserved the right not to give out information.

The security agencies' case is likely to be weakened by undertakings from Justice Minister Penuell Maduna, who is also being investigated by the commission for alleged abuse of office, and Ngcuka. They have waived their privileges and rights, and are prepared for information held on them to be divulged.

Arendse suggested that retired judge Joos Hefer apply for protected disclosure, where parties would sign an oath of secrecy before viewing the information. Kessie Naido, who is leading evidence for the commission, said security agencies could not possibly want blanket protection when they allowed classified documents to leave their shelves.

This drew a sharp objection from George Bizos SC, representing the security agencies, saying there was a difference between allowing documents to leave the shelves and them being stolen.

"If people have documents, why ask for them from us?" said Bizos, in reference to documents Shaik produced in an interview.

With acknowledgements to Xolani Xundu and the Business Day.