A deputy director at Statistics South Africa, Jairo Arrow, and a senior statistician, Marlize Pistorius, apparently made mistakes that would have provided wrong figures of the census by province, as well as an incorrect national figure.
"The evidence is that the results they presented were totally wrong and there were methodological and computational errors in what they presented to me," statistician-general Pali Lehohla was quoted as saying by City Press.
He repeatedly asked them to find the problems and correct them.
"Ms Pistorius and Dr Arrow argued that the results they presented to me in July would not change," he said.
Arrow presented a written apology to Lehohla and went on early retirement last Friday after facing a disciplinary hearing for "dereliction of duty and gross incompetence".
Pistorius was also facing a disciplinary hearing, which would resume in February.
She was responsible for the post-enumeration survey. This is a second, smaller population count used to determine by how much the initial census results have to be adjusted.
University of Cape Town statisticians, Tom Moultrie and Rob Dorrington, had publicly raised concerns about the integrity of the post-enumeration survey and the reliability of the final count.
The census cost R3.4-billion. The results are used to allocate about R350-billion in government funds each year, City Press reported. – Sapa