Venezuela's Mining Minister Victor Cano on Wednesday said the central bank was exporting gold to Turkey rather than Switzerland due to concerns about sanctions, without specifying the amount that was being sent.

The latest data on Turkey's Statistical Institute website show that between January and May, Venezuela exported 20.15 tonnes of gold to Turkey, compared with none in 2017. Turkey did not send an equivalent amount of gold back to Venezuela, the data showed.

Cano on Wednesday said the gold exported to Turkey would ultimately return to Venezuela to become part of the central bank's portfolio of assets.

The Venezuelan Central Bank did not respond to a request for comment.

Crisis-stricken Venezuela since last year has been buying gold from small miners in the southern jungle region of the country in order to shore up its flagging monetary reserves.

Cano on Wednesday said the central bank had bought 17.6 tonnes of gold through these operations. The central bank maintains 150 tonnes of gold reserves and in previous years it purchased minimal amounts, according to its own data.

All of Venezuela's gold exports had been registered in the Turkish official data as "non-standard unrefined gold," which according to dealers represents unrefined gold that does not fulfill the purity criteria of 99.99 percent.

The Venezuelan central bank is buying bars from miners which have a purity grade of between 88 percent and 98 percent, Cano said. The bars must be refined and certificated as "monetary gold" so it can enter Venezuela's reserve and be used in future financial operations, he said.

In previous years, Venezuela certificated a portion of its gold in Switzerland in order to back-stop deals with banks that were providing the government with much-needed loans while global petrol prices were plummeting.

Data from Turkey's Statistics Institute does not show any gold exports back to Venezuela in 2018, so it is possible the refined gold is being sold there or in other markets.

"This Venezuela issue was first raised a few years ago. A delegation had come from Venezuela and held talks with some players in the Turkish gold market," a partner in an Istanbul-based precious metals firm said.

"The (import) numbers are not that large. Of course they do attract attention as these transactions were not made before," the partner said. (Reporting by Humeyra Pamuk and Behiye Suelin Taner in Istanbul and Corina Pons in Caracas; writing by Brian Ellsworth; editing by Angus Berwick and Richard Chang)