A Russian oil tanker suspected of breaking the trade embargo on Iraq is being diverted to a secret location.

The US-led Multinational Interception Force (MIF), which helps enforce the embargo, stopped the ship in Gulf waters.

A US Navy spokesman said an inspection team had gathered sufficient evidence to suggest the tanker's cargo was illegal, although tests on the oil have yet to be completed.

Correspondents say ships seized for breaching trade embargoes are usually taken to an anchorage in international waters until a country in the Gulf has agreed to take the vessel, which it is then allowed to sell.

Russia says the tanker was carrying Iranian oil and has demanded the ship's immediate release.

The Russian Interfax news agency quoted Deputy Foreign Minister Vasily Seredin denying that the Volgoneft-147 tanker was carrying Iraqi oil.

"The vessel never entered Iraqi waters or Iraqi ports," he said.

But Pentagon spokesman Jim Kout said the MIF boarded the ship early "on suspicion that it was implicated in the illegal transportation of Iraqi oil".

MIF spokesman US Commander Jeff Gradeck said the ship was tracked "beginning with its departure from Iraqi waters".

Repeated protests

Mr Seredin said Russia had "expressed its puzzlement" over the incident to the US and the United Arab Emirates.

One unnamed senior official was quoted as saying the action "could have a negative impact on US-Russia relations".

Correspondents say the United States has repeatedly protested to Russia about suspected smuggling activities, occurring in defiance of United Nations sanctions imposed after Iraq invaded Kuwait in 1990.

Iraq has been unable to sell its oil on the open market since the sanctions were imposed.

In 1996, the UN Security Council launched the oil-for-food programme which allows Iraq to export limited amounts of oil to buy food and medicines for its people