Russia has started supplying grains, equipment and construction materials to Iran in exchange for crude oil under a barter deal, Russian Deputy Foreign Minister Sergei Ryabkov said yesterday.

Russia has been an ally of Iran in international talks over Tehran’s nuclear programme that have led to an interim deal under which Iran would curb the programme and allow international control in exchange for ending economic sanctions.

Russia hopes to benefit from any such move if the preliminary nuclear agreement is followed by a technical one as planned by the end of June and has already moved ahead with an oil-for-goods swap.

“I wanted to draw your attention to the rolling out of the oil-for-goods deal, which is on a very significant scale,” Ryabkov told Russian senators.

“In exchange for Iranian crude oil supplies, we are delivering certain products. This is not banned or limited under the current sanctions regime,” he added, declining to give more details.

Iran is the third largest buyer of Russian wheat, and Moscow and Tehran have been discussing the deal since early 2014.

Sources told Reuters a year ago a deal worth up to $20 billion was being discussed that would involve Moscow buying up to 500,000 barrels of Iranian oil a day in exchange for Russian equipment and goods.