Census officials and statisticians stand by their figures and claim that the failures were caused by other factors, such as inefficiency and deliberate tampering with the ballot.
The Independent Electoral Commission, the body responsible for running the election, estimated that there were 22.7 million potential voters and printed 80 million ballot papers. But when some polling stations ran out of ballot papers on Wednesday and others never received election materials at all, they were forced to print an extra 6 million ballot papers and fly them to polling stations. Several million ballot papers had gone missing, some were found thrown away, hidden or even burnt in deliberate attempts to manipulate or thwart the election.
'An investigation is designed to establish whether there was an administrative cock-up and logistical inefficiency or whether there was dirty work at the crossroads,' said one IEC official. 'I guess it was about half and half.'
However, neither can explain how estimates of the numbers of voters were so wildly inaccurate in some areas. The 1991 census, combined with the figures from the nominally independent 'homelands', gave a total population of 38.5 million people of whom about 30 million were black.
The IEC accepted these figures. Yet even as it was planning the election its voter estimate jumped from 18 million to 22 million. It planned 9,000 polling stations, expecting 3,000 voters each.
The figures, however, were suspect. In its 1992 report the Central Statistical Service admitted that the black population figure was 'shrouded in the highest degree of uncertainty'. There were 88 areas, mostly the vast squatter camps and peri-urban areas, which had to be surveyed by aerial photography, followed up by sampling on the ground. The figures were then extrapolated.
Ellen Porter of the Institute of Race Relations said: 'In some black areas it is impossible to get truthful answers because people are very suspicious of officials. Secondly, the census was not conducted in the homelands or the former independent states.'
Dr Treurnicht Du Toit, head of the Central Statistical Service, vigourosly defends his methods and figures and rejects the idea that black people would be afraid to tell the truth. 'That may have been a factor in the past, but not in 1991. People say there are 3 million people in Soweto, but frankly that's impossible, translated into an average per household . . . If there is a divergence between our figure and the number of ballots cast you must look at other factors, such as illegal voters.'
His view is supported by Jabu Sindane of the Human Sciences Research Council, who said: 'The census could not be out by 10 per cent. The voter estimate was 22.7 million. I doubt if it could go beyond 25 million. The chaos is just another botch-up by the IEC.'
It is probable that the chaos will result in the election being invalidated in some areas and, according to the rules, rerun in those areas within 12 days.