STATISTICS on employment that were due for publication by Statistics SA on Tuesday have been delayed as it combs through anomalies that arose last year when a new master sample was introduced.

Stats SA said on Monday that results of the fourth-quarter Quarterly Labour Force Survey would not be published this week as expected, but at the end of the month, fuelling speculation in some quarters that the delay was political and a bid to conceal bad news ahead of the state of the nation address and budget speech.

Stats SA said the reason for the postponement was that a parallel survey had been run in the fourth quarter to identify anomalies that arose after the introduction of a new master sample last year.

"Additional time is required to churn the results of the parallel survey with the fourth-quarter results," Stats SA said.

On Wednesday, statistician-general Pali Lehohla said the fourth quarter survey results had not shown startling deviations from the trend. At the end of the third quarter, unemployment stood at 25.5%.

A new master sample of the Quarterly Labour Force survey of 30,000 households was drawn up on the basis of the census data.

"In the new sample, the number of employed remained broadly the same, as did the number of unemployed, when discouraged workseekers and those actively seeking work were counted together. What changed was the share between those who were unemployed, but were seeking work and those who were unemployed; and were not actively seeking work. So, we ran a parallel survey to see what had happened," Mr Lehohla said.

He said Stats SA followed a forward calendar in publishing results that was changed only for compelling reasons. The state of the nation speech would not be considered a compelling reason.

Several economists and statisticians said on Wednesday the explanation provided was plausible and the results genuinely needed more time to process.

Associate professor in economics at the University of Cape Town, Martin Wittenberg, said: "There may be more anomalies that Stats SA has picked up, given the shift when they switched to the new master sample at the beginning of 2015.

"They’re trying to figure out what is driving the results. It is more likely StatsSA trying to protect its own reputation by delaying the results, rather than any concerns over the state of the nation address."