Turkey on Friday acknowledged that a surge in its gold exports this year is related to payments for imports of Iranian natural gas.

The continuing trade deal offers the most striking example of how Iran is using creative ways to sidestep Western sanctions over its disputed nuclear program, which have largely frozen it out of the global banking system.

The disclosure was made by Turkey's Deputy Prime Minister and top economic policy maker Ali Babacan in answers to questions from the parliamentary budget committee.

Iran provides 18% of Turkey's natural gas and 51% of its oil. But since U.S. and European Union sanctions ban Tehran from receiving payments in dollars or euros, Ankara pays Iran for the gas in Turkish liras. The lira is of limited value for buying goods on international markets but ideal for purchasing Turkish gold. The government hasn't specified how it pays for Iranian oil.

"In essence, gold exports [to Iran] end up like payments for our natural gas purchases," Mr. Babacan said. "Turkey is depositing the payment for the gas we purchase from Iran to Iran's account in Turkey…I don't know exactly how they then transfer it," he said.

Turkey sold $6.4 billion of gold to Iran in the first nine months of this year, up from just $54 million in 2011, according to official data, tripling Ankara's exports to its eastern neighbor and almost evening the trade balance that historically has been dramatically in Tehran's favor. Iran accounts for 60% of Turkey's gold exports this year, followed by the United Arab Emirates with 30% of the total.