Ambiguity surrounds the fate of an oil tanker pulled by Iran for its territorial waters

WASHINGTON (Reuters) - US officials said they were not sure whether Iran had seized an oil tanker and pulled it into Iranian waters, or had rescued it after experiencing a technical failure, Tehran says, creating uncertainty as tensions mount in the Gulf.

The ship disappeared from the ships' traffic monitoring maps when its transmitter was closed in the Strait of Hormuz on July 14. The last site spotted the tanker off the coast of the Iranian island of Qeshm in the Strait.

Iran says it withdrew a ship to its territorial waters from the strait after sending a distress signal. Tehran did not name the ship, but "wind" is the only vessel that matches its record of what has been described.

A US official, speaking on condition of anonymity, said the tanker appeared in Iranian territorial waters, but it was unclear whether it was because Iran was holding it or because it had rescued it.

The mystery comes at a time when Washington has called for greater security for ships in the Gulf.

Threat and denunciation
Iran had threatened to retaliate against Britain's seizure of an Iranian oil tanker it accused of violating sanctions against Syria. Supreme Leader Ayatollah Ali Khamenei described the British move as "piracy."

The United States has also blamed Iran for attacks on tankers in the Gulf since May, a charge Tehran denies.

US sanctions against Iran, aimed at halting its oil exports, have led to an increase in the unusual movement of carriers away from shipping lines, as Iran is looking for clandestine routes to export its oil, cargo experts say.

The closure of ships has increased positioning devices while transporting oil by sea to conceal their routes. Iran's reliance on a fleet of old ships, some of which are being withdrawn for emergency repairs, has also increased.

Adding to the ambiguity surrounding the lost vessel is the difficulty of knowing its owner, and no state or company has so far declared ownership of it.

Initial reports said it was Emirati, but an UAE official said the tanker was not owned by the UAE or operated by the UAE.

The airline that operates the tanker is Prime Tankers in the UAE. The company said it had sold the tanker to the UAE-based company, "Wave Sea".

"The company does not own the tanker, but it has been operating for two months now and is now under the management of another company," said a staff member at Moj Bahar.