The SA Revenue Service must urgently examine its trade figures, T-SEC economist Mike Schussler said on Monday.

"These are dangerous economic times and this needs to be seen to quickly," Schussler said.

His comments followed a report in Business Day that the country's trade deficit last year may have been overstated by at least R18 billion.

"Trade figures all over the world are never easy to predict, but the problem is size of the supposed error, R18 billion is a large mistake," Schussler said.

The error was reportedly discovered by Tariff & Trade Intelligence and IHS Global Insight and was confirmed by the Bureau For Economic Policy and Analysis at Stellenbosch University.

Efficient Group economist Dawie Roodt said he and his colleagues had picked up the error some time ago and had made inquiries, but were not provided with further information.

"I expect the problem lies with gold, as we import unrefined gold from the US and even China, because South Africa has the capacity to refine that gold further," Roodt said.

He added that South Africa's gold production had been in a slump for a considerable period, so extra refining capacity was available.

"I think we import gold to refine it further and we then export it back -- and when exports are considered, only the local gold exported is taken into account."

The fact that the country had become a precious metals importer could not be correct, Roodt said.

"If you work with these sorts of numbers and you see that there is a clear change in the trend -- you should pick it up.

"Sars should have told us," Roodt said.

Sars could not be reached for comment.