But Katada offered an alternative version of how the events unfolded.
"To put a bomb on the side is not something we are thinking," he said. "If it's between an explosion and a penetrating bullet, I have a feeling it is a penetrating bullet. If it was an explosion, there would be damage in different places, but this is just an assumption or a guess."
On Thursday, company officials said the vessel, which had been carrying methanol from Saudi Arabia to Singapore, had first been hit by what appeared to be an artillery shell toward the stern, causing a fire in the engine room which they had been able to extinguish.
Three hours later, the ship was again attacked on the same side in the center of the hull, at which point the captain felt it was no longer safe and ordered the crew to take to the life boats, officials said.
"When the shell hit, it was above the water surface by quite a lot," Katada said Friday. "Because of that there is no doubt that it wasn't a torpedo."
The ship's crew saw an Iranian military vessel in the vicinity on Thursday night Japan time, Katada said, according to Reuters news agency.
US President Donald Trump blamed Iran for attacks on two oil tankers at the entrance to the Gulf despite Tehran's denials, raising fears of a confrontation in the vital oil shipping route.
Iran has dismissed earlier US charges that it was behind the attacks that crippled two tankers. It has previously suggested it could block the Strait of Hormuz, the main route out for Middle Eastern oil, if its own exports were halted.
Iran has accused the United States and its regional allies such as Saudi Arabia and the United Arab Emirates of "warmongering" by making accusations against it.
Asked how he planned to address Tehran and prevent any further incidents, Trump told Fox News: "We're going to see." He also said any move to close the Strait of Hormuz would not last long.
Nevertheless, Trump, who last year pulled the United States out of an agreement between world powers and Tehran to curb Iran's nuclear programme in return for the lifting of sanctions, said that he was open to negotiations with Iran.
Iran has repeatedly said it will not re-enter talks with the United States unless it reverses Trump's decision to withdraw from the nuclear deal.
Tehran and Washington have both said they have no interest in starting a war. But this has done little to assuage concerns that the two arch foes could stumble into a conflict.
China, the European Union and others have called for restraint from all sides.
Washington Post, AP