Nearly 20 years ago, Rosemary Woods, Richard Nixon's personal secretary, maintained she had 'accidentally' erased a vital 17 1/2 minutes of taped conversations between her boss and his aides in which they discussed the cover-up of the Watergate burglary.
Yesterday morning in Vereeniging, five miles east of Boipatong, Sergeant Elsa O'Reilly told Justice Richard Goldstone that she had accidentally erased 13 hours' worth of tape-recordings of police radio transmissions before, during and after the massacre. The importance of the evidence contained in the tapes is that they would either confirm or refute evidence provided by a number of witnesses - the latest, yesterday afternoon, a black policeman - that police in armoured vehicles assisted the Inkatha attackers on the night of 17 June, when 41 died.
Sgt O'Reilly's testimony was confusingly technical at times, but in essence this was her explanation: a recording machine was installed at the Vereeniging headquarters of the Internal Stability Unit - the new name for the riot police - where she works in the operations control room, on 24 March this year. The machine, connected to telephone and radio lines, uses ordinary cassette tapes.
She mastered all of the machine's complex functions save for one. She did not know that if she turned the tape around from Side A to Side B, Side A would be wiped out during recording. 'I was never told I could record only one side of the tape and it is not indicated anywhere in the manual,' she said.
Three months passed, she said, before she was made aware of her mistake. It was only a week after the massacre, she said, that she learnt from a police investigating officer to whom she had given the tapes that they had been erased. She had handed tapes previously to officers working on other investigations but no one had drawn her attention to the problem.
A Law and Order Ministry spokesman, Craig Kotze, told the press yesterday: 'The tapes were accidentally erased. There was no sinister motive or foul play. We have nothing to hide in connection with the Boipatong killings.'