Kamran Jebreili, Associated Press
In this Jan. 19, 2012 file photo, a plane flies over the mountains in south of the Strait of Hormuz as the trading dhows and ships are docked on the Persian Gulf waters near the town of Khasab, in Oman.

TEHRAN, Iran — A Marshal Islands-flagged cargo vessel seized by Iranian forces as it was traversing the Strait of Hormuz last month will likely be released in two days, after it pays a fine, Iran's Foreign Ministry spokeswoman said Wednesday.

The April 28 seizure of MV Maersk Tigris followed a legal complaint by an Iranian private company, Marzieh Afkham told reporters during her weekly press conference.

"This is an absolutely legal matter," she said. "The ship has a private plaintiff and there was a lawsuit in progress against it. The vessel was seized as it entered Iran's territorial waters."

Afkham added that "negotiations between the private complainant and the other party" were underway and that, "based on the information we have acquired, it is likely that the dispute will be settled within the next two days."

Iranian forces boarded the ship after firing warning shots across the bridge and later took it to Bandar Abbas, the main port of Iran's navy, under escort by Iranian patrol boats. Danish shipping company Maersk Line, which chartered the container ship from Rickmers Ship Management in Singapore, insisted it had no "special cargo" such as military equipment.

The incident came at a critical time in Iran's relations with the United States and the West, as talks on Tehran's contested nuclear program continue and frictions rise amid a U.S.-backed campaign by a Saudi-led coalition carrying out airstrikes against Iranian-backed Shiite rebels in Yemen.

In Tehran, the semi-official Mehr news agency Wednesday quoted Iran's navy chief, Adm. Habibollah Sayyari, as saying Maersk has to pay a fine in order for the ship to be released.

"A judicial verdict has been issued against the company. They must pay the fine," Sayyari said without elaborating on the amount.

Rickmers spokesman Cor Radings would not comment on a possible fine, reiterating only in an email that his organization was in dialogue with the Iranian courts.

And in Copenhagen, Maersk Line spokesman Michael Storgaard, who on Tuesday confirmed a "dialogue with the Iranian courts," also declined immediate comment.

Following the Maersk incident, Washington adopted a policy change, allowing any U.S.-flagged ship to be accompanied by Navy warships through the narrow strait, which includes Iranian territorial waters. Navy ships are positioned nearby and are ready to respond if needed, but they do not actually escort a vessel.

The Strait of Hormuz is the route for about a fifth of the world's oil and is only about 33 kilometers (21 miles) wide at its narrowest point. Ships traversing the chokepoint have even less room to maneuver. The shipping lane in either direction is only 2 miles wide, with a 2-mile buffer zone between them.

Associated Press writers Jan M. Olsen in Copenhagen and David Rising in Berlin contributed to this report.