A second member of the Royal Navy crew captured in the Gulf has apologised for trespassing in Iranian waters, in a broadcast on Iranian television.

He was quoted as saying: "We entered Iranian waters without permission and were arrested by Iranian coastguards.

"I would like to apologise to the Iranian people for that."

The Foreign Office described the latest "confession" video as "disgraceful exploitation". The UK denies the crew had trespassed.

Iranian state news agency IRNA named the crewman as Nathan Thomas Summers.

On Wednesday, the only woman, Leading Seaman Faye Turney, was shown on Iranian TV making similar comments. The UK denies the crew had trespassed.

The latest video came as Iranian President, Mahmoud Ahmadinejad, called on Britain to apologise to Tehran.

On Friday, the UN Security Council agreed a statement voicing "grave concern" at Iran's actions.

The statement also calls on Tehran to allow the UK consular access to the personnel and an "early resolution" including release of the crew, but stops short of "deploring" Iran's action, as requested by the UK.

Iran said it was not helpful to try to engage third parties in the dispute.

Later, European Union foreign ministers are expected to express their solidarity with Britain, at a meeting in Germany, over the detention of the navy crew.

The Foreign Office said a "formal note" had been sent to the British embassy by the Iranian government.

Confidential

A spokeswoman said: "Such exchanges are always confidential, so we cannot divulge any details, but we are giving the message serious consideration and will soon respond formally to the Iranian government."

Sir Menzies Campbell, the Liberal Democrat leader, said the note may contain "matters of substance" which may be the beginning of a "proper exchange" and could "offer the possibility of a solution".

On a visit to British troops in Afghanistan on Friday, Chancellor Gordon Brown welcomed the UN resolution.

He said: "The UN resolution is calling definitively for [the navy crew's] release. That's the unanimous view of the international community."

Mr Brown described the treatment of captured Leading Seaman Faye Turney, 26, an interview with whom has been shown on Iranian TV, as "cruel, callous, inhuman and unacceptable".

Responding to the UN statement, David Cameron, the Conservative leader, said: "Really there's only one right outcome to this which is for Iran to release those people that they took captive, that they should be released without any further ado. It's as clear and as simple as that."

The British ambassador to the UN, Sir Emyr Jones Parry, said the UN's statement was a "good outcome" for the UK.

Sir Emyr added that it sent the "right message" to Iran to allow access to the sailors and marines, and secure their prompt release.

The UK failed to win support for a stronger statement deploring Iran's actions, following opposition led by Russia.

Iran's UN mission said in a statement: "This case can and should be settled through bilateral channels.

"The British government's attempt to engage third parties, including the Security Council, with this case is not helpful."

The UN Security Council statement was agreed following more than four hours of negotiations on Thursday.

The Britons, based on HMS Cornwall, were seized a week ago by Iranian Revolutionary Guards as they returned from searching a vessel in the northern Gulf.

Iran says they had strayed into Iranian territorial waters, a claim which the UK has denied.

Earlier this week, the Royal Navy produced satellite data it said proved its case.