The Hefer commission has issued a subpoena for former Sunday Times journalist Ranjeni Munusamy to testify before it, saying her argument that it would be unethical to reveal her sources is no longer valid.

Commission spokesman John Bacon said yesterday that testimony to the commission last week had revealed that much of the documentation which formed the basis of the news stories she co-wrote in City Press had come from former intelligence officer Mo Shaik.

Now that the source of the news stories was known, the commission intended pressing its claim for Munusamy to take the witness stand.

The commission is investigating whether Scorpions chief Bulelani Ngcuka was an apartheid spy. It heard last week how Shaik had given Munusamy a reconstructed document that his African National Congress counterintelligence unit had drawn up in the late 1980s.

Munusamy has resisted giving evidence at the commission, arguing that it would be both contrary to her journalistic ethics to reveal her sources and could put her life in danger. However, the Bloemfontein High Court refused to excuse Munusamy from testifying before the commission.

Judge President JP Malherbe said that the commission's decision that she had to give evidence with the right to object to certain questions did not violate any of her constitutional rights.

Munusamy has said previously that she intends appealing against this decision, and papers must be in by tomorrow. But the commission decided to issue a warning that she must come forward despite the possibility of an appeal, partly to expedite the hearings.

Munusamy said yesterday she intended to pursue the appeal process and did not accept the argument that the source of the documents was known. More than 18 people were involved in a thorough checking procedure before her story was published, and she undertook to keep the sources' identities secret.

She also said she was worried about the "collateral damage" that might be caused if she gave evidence to the commission, especially in the light of the harm that had already been caused to various people.

With acknowledgements to Tim Cohen and the Business Day.