 Halkbank seems, between March 2012 and July 2013 while the UN sanctions regime was in place prior to the November 2013 P5+1 agreement, to have purchased some $13bn worth of gold on the open market.The sanctions prevented Iran from being paid in dollars or euros, but gold was never mentioned in the sanctions regime, and therefore this loophole allowed gold to be used to fund the purchase of Iranian petroleum products.Halkbank allowed the middlemen of Iran to buy gold with their Turkish lira, and that gold found its way back to Iranian coffers.