Iran has smuggled in at least $1 billion in recent months, evading U.S. sanctions prohibiting the purchase or acquisition of U.S. bank notes by the government of Iran. According to Western and Iranian sources, the Central Bank of Iran has worked with Iranian entities and front companies to obtain dollars from abroad. After passing through money changers and front companies, cash was hand-carried on flights from Dubai or Turkey, or brought over the border from Iraq. About $500 million in cash was reportedly brought into Iran using traders in Iraq, while two Dubai-based front companies, Sima General Trading Company and Belfast General Trading, were responsible for obtaining another $500 million. Both front companies have been previously sanctioned by the U.S. Department of the Treasury.