Top-level probe into crew capture

Rules of engagement, equipment and procedures will all be analysed, amid reports the Royal Navy had stopped boarding ships in the northern Gulf.

An MoD spokeswoman would not confirm that. She said: "The coalition boarding operations continue. A full UK contribution will recommence but no timescale has been set. HMS Sutherland will be patrolling while Cornwall (the captured crew's ship) goes off for replenishment, maintenance and crew stand-down."

Iran accused the 15 crew of straying into its waters, although the British have insisted throughout that they were in Iraqi territory.

Meanwhile, military experts will continue quizzing the 15 freed by Iran about their ordeal. They are also due to undergo a medical.

It was BBC Radio 4 who reported boarding operations in the Gulf had been suspended. It also said the 15 detained sailors and marines comprised one of only two crews responsible for boarding vessels in the area.

Shadow defence secretary Liam Fox said it looked like Iran had succeeded in driving British vessels out of Gulf waters. He suggested that the Navy should resume its presence at the end of the investigation.

Sir Menzies Campbell, the Liberal Democrat leader, said such a decision depended on the findings of the investigation. But he added: "I'm among those who have been arguing it's time for British forces to leave Iraq."

The 14 men and one woman who were held in Iran for 13 days flew home on Thursday on a scheduled British Airways flight from Tehran.

It is understood that the group will continue staying at the Royal Marines Base Chivenor, near Barnstaple, north Devon.