Danish shipping group A.P. Moeller-Maersk said Wednesday that the crew of a chartered cargo vessel seized by Iran was safe, and that the company had been told a cargo dispute was behind the ship's confiscation.
Iran's elite Revolutionary Guards intercepted the Maersk Tigris on Tuesday in the strategic Strait of Hormuz leading into the Gulf.
The Marshall Islands-flagged ship was operated by Rickmers Ship Management, with head offices in Singapore and Hamburg, and was carrying cargo for Maersk Line, the group's shipping unit which had chartered the ship.
"We are in ongoing contact with Rickmers Ship Management and are pleased to learn that the crew is safe and under the circumstances in good spirits," Maersk said in a statement.
"We are continuing our efforts to obtain more information about the Iranian authorities' seizure -- in international waters -- of Maersk Tigris," it added.
The managing director of the Iranian Ports and Maritime Organisation, Mohammad Saidinejad, told Iran's official IRNA news agency that the confiscation was ordered after a private company on March 16 filed a complaint against Maersk over unpaid debts.
Maersk said it had been told by the agency that the seizure of the ship was related to "an allegedly unresolved cargo claim."
"We have however not received any written notification or similar pertaining to the claim or the seizure of the vessel," the shipping company added.
As such it said it was unable to confirm "whether or not this is the actual reason behind the seizure", but would continue its "efforts to obtain more information."
The Iranian embassy in Copenhagen said late Wednesday the dispute was over a 10-year-old unpaid debt and that there were no political motives or security concerns behind the move.
The Danish embassy in Tehran had been kept informed about the case over the years and the ship would be allowed to continue its journey as soon as Maersk settled its debt, the Iranian embassy said in a statement quoted by news agency Ritzau.
A spokesman for the Danish foreign ministry told AFP it was "following the situation closely" and that it was "in close dialogue" with Maersk.
The container vessel had a 24-member crew and was carrying regular commercial cargo but nothing related to weapons, according to Cor Radings, a spokesman for Rickmers.
Most crew members were from Eastern Europe and Asia, he told Danish media.
Iranian military ships on Tuesday fired across the bow of the Maersk Tigris when the captain initially refused a demand to head towards Iranian territory, US government and cargo company officials said.
The ship seizure came against the backdrop of heightened tensions in the Gulf, fuelled by the conflict in Yemen and high-stakes diplomacy between Washington and Tehran over Iran's nuclear program.