THE British envoy to Tehran yesterday requested access to 15 detained British naval personnel who Iran says entered Iranian waters illegally although Britain has said they were in Iraqi territory, a diplomat said.

Iranian forces captured 15 British sailors and marines Friday at the mouth of the Shatt al-Arab waterway, which marks the southern stretch of Iraq's border with Iran.

It has raised tensions that are already high with the West over Tehran's nuclear program.

Britain's Ambassador Geoffrey Adams met Iranian Foreign Ministry official Ebrahim Rahimpour to discuss the issue at London's request, a British diplomat in Tehran said.

"We have repeated the line asking for their release. We asked for details of where they are and asked for consular access," the diplomat said.

"The (Iranian Foreign Ministry) promised to look into these requests and dialogue is continuing," the diplomat added.

Iranian television reported the meeting, without giving details. But it said the British envoy had been summoned.

Iran's semi-official Fars news agency reported Saturday that the 15 sailors and marines had been transferred to Tehran. But this has not been independently confirmed.

"We are asking to know whether they are being moved around inside Iran," Foreign Office Minister David Triesman told Sky News.

He said differences over where the British personnel were when detained by Iranian forces could be "technically resolved."

"I have been very clear throughout that British forces do not ever intentionally enter into Iranian waters," he said.

Jack Straw, leader of the House of Commons and former Foreign Minister, said that one of those detained was a woman and said resolving the row "requires some very careful and intense diplomacy."

Britain said two boatloads of Royal Navy sailors and marines had searched a merchant vessel on a U.N. approved mission in Iraqi waters when Iranian gunboats encircled and captured them.

An Iraqi fisherman who said he saw Iranian forces detain them, said Saturday the ship British forces were searching was anchored in Iraqi waters.

The incident sent oil prices to a three-month high Friday. It took place a day after Iran launched a week of naval war games along its coast, including the Gulf's northern reaches which give access to the oil output of Iraq, Iran and Kuwait.

(SD-Agencies)