In a regulatory filing, the New York-listed tanker owner told the agency’s watch dogs that more than a dozen vessels tied to spot and time charters called on ports in Iran and Sudan on over 48 separate occasions between 22 November 2010 and 29 January 2012.

In 2011, Frontline said operating revenues generated by voyage charters with port calls in two of the countries subject to US trade embargoes amounted to $29.9m,