From Israel's Ministry of Foreign Affairs, we can see:
A copy of the ship's manifest, showing that the cargo was being shipped by the Iranian company IRISL (Islamic Republic of Iran Shipping Lines) and that the description of the goods was "poly ethelyne" (click to enlarge)

IRISL's stated vision starts off by saying "By trusting in Almighty's grace & eternal power, inspired by the long-term visions of the sacred system of the Islamic Republic of Iran...." It is clearly not an independent company.
Even more explicit were labels for explosives that say "Ministry of Sepah," which is a branch of Iran's armed forces:

The bags of polyethelyne were also manufactured in Iran:



If Iran goes to such lengths to hide its illegal shipments to Hezbollah terrorists, what do you think they are doing to hide their nuclear weapons program?
