The official IRNA news agency aired the comments of Ali Shamkhani of the Supreme National Security Council on Saturday, a day after two missiles struck the Iranian tanker Sabiti as it traveled through the Red Sea off the coast of Saudi Arabia.
Shamkhani says a committee in Iran has obtained some information from video images from the Sabiti.
Also on Saturday, Cabinet spokesman Ali Rabiei said Iran is investigating the case while "avoiding hastiness."
The mysterious attack, which came amid months of heightened tensions at sea across the wider Mideast, damaged two storerooms aboard the tanker.
There's been no comment from Saudi Arabia, which in September had more than half of its daily crude oil production knocked out by an assault the U.S. blamed on Iran.