A CBS News investigation reveals China's continued evasion of US sanctions on Iranian oil through a "dark fleet." These ships, operating in international waters, conduct ship-to-ship transfers to conceal the origin of Iranian crude bound for China. The practice, witnessed firsthand by CBS News, involves turning off transponders and obscuring ship identities. This illicit trade, estimated to generate $70 billion annually for Iran, fuels concerns about funding for Iran's nuclear program despite increased US sanctions.

Prepared by Rachel Morgan and reviewed by editorial team.