The DA said it was alarmed that formerly classified information was given to national police commissioner Jackie Selebi's lawyers in what the party believes was a violation of the laws on communication interception.

Democratic Alliance safety and security spokesperson Dianne Kohler Barnard on Tuesday said the party would ask the inspector general of intelligence Zola Ngcakani to investigate.

She said the DA would write to Ngcakani to ask him to add the "Selebi tapes" to the investigation into possible irregularities surrounding the disclosure of tapes in the trial of African National Congress president Jacob Zuma.

This was in response to the National Prosecuting Authority's (NPA) submission in the High Court in Johannesburg on Monday that the police had declassified information and given it to Selebi's lawyers in preparation for his trial on corruption allegations.

"Again, state intelligence officials are providing copies of intercepted communication material to private individuals, and it is unclear that they are legally entitled to do so.

"Why do the lawyers of politically well-connected suspects in criminal cases receive such preferential treatment?" asked Kohler Barnard.

The party believes authorities appear to have ignored the Regulation of Interception of Communication Act of 2002, which it said specifies that intercepted communication material can only be released publicly in specific circumstances.

"Though the police may be able to declassify certain material, legislation provides citizens with certain rights to privacy, so it does not automatically follow that such information can be made public, or indeed passed on to Mr Selebi's lawyers," she said.

"Any state agency that decides to release intercepted communication publicly must also prove that doing so meets the requirements of the legislation. This issue appears to have been completely ignored."

Zuma's corruption prosecution was abandoned after the NPA said it had heard taped conversations of former NPA officials Bulelani Ngcuka and Leonard McCarthy and construed the substance of the conversations as interference in the prosecution process.

At Selebi's court hearing on Monday, the State complained that while they had a lengthy struggle to get information from the police for their investigation, they discovered last week that information was declassified and handed over to Selebi's lawyers.