The sanctions had prohibited the country from obtaining the required US dollars to carry out international transactions.
Reuters has cited unidentified sources as saying that as much as $500m was funneled to the country through traders and another $500m was obtained by two front companies in Dubai.
Interviews conducted by the news agency with Iranian officials, Western diplomats and intelligence sources, revealed that Iranian central bank played a key role in the smuggling issue.
Tehran had been on look out for new ways to obtain dollars since March 2014.
Money changers and front companies in Dubai, the UAE, and Iraq were involved in transactions where cash was passed prior to reaching Iran.
The central bank was said to be a driving force in efforts to obtain dollars.
In 2014, the UN Security Council’s Panel of Experts released a report on Iran, which said that the country had used cash and money changers to help get around restrictions on banking.
"The Panel continues to receive information from states and financial institutions that Iranian companies could operate through trading companies or shell companies in neighboring states," the report said.
Image: Iran smuggled $500m through traders and obtained another $500m from two front companies in Dubai. Photo: courtesy of sheelamohan/FreeDigitalPhotos.net
