Maersk said on Wednesday Iranian authorities had told it the Maersk Tigris vessel had been seized over an unresolved claim, but as it had not received any documents it could not confirm this had been the reason for Iran's actions.
Iranian patrol boats on Tuesday fired warning shots as they intercepted the vessel in one of the world's busiest oil shipping lanes, spurring the United States to send military vessels to monitor the situation.
"They (Iranian authorities) informed us that the seizure of Maersk Tigris is related to an allegedly unresolved cargo claim," Maersk said in a statement. "We have however not received any written notification or similar pertaining to the claim or the seizure of the vessel. We are therefore not able to confirm whether or not this is the actual reason behind the seizure."
(Reporting by Sabina Zawadzki; Editing by Janet Lawrence)