The future of the Monchegorsk, now anchored off Cyprus, remains unclear
Iran has denied reports that a ship detained off Cyprus is carrying Iranian weapons destined for the Hamas-controlled Gaza Strip.
The US military reportedly stopped the ship last month in the Red Sea and said it found artillery shells and other arms on board.
Cyprus says the vessel has breached a UN ban on Iranian arms exports.
The Cypriot-flagged Monchegorsk is now anchored off the port of Limassol under tight security.
Iranian Foreign Ministry spokesman Hassan Ghasghavi told a news conference: "The ship was not taking arms and weapons (to Gaza)."
Cypriot authorities had inquired about the ship's cargo and "if it was carrying weapons things would have been clear", he added.
On Tuesday Cypriot Foreign Minister Marcos Kyprianou said a UN committee ruled that the Monchegorsk was in "clear" breach of UN sanctions, but he did not specify what had been found on board.
The ship was detained by Cypriot authorities reportedly on requests by the United States.
Cyprus needs to decide whether it will confiscate the cargo or send it to a third country, following consultations with UN Security Council members. Sending the shipment back has been ruled out.
Israel has long accused Iran of arming the Islamists in Gaza, a claim Tehran denies even though it says it offers moral support to Hamas.
In December, Israel began a 22-day offensive against Hamas in Gaza, attempting to end rocket attacks by militants on southern Israeli towns.