Iranian television on Wednesday displayed some of 15 British sailors and marines detained at sea last week, and included the only woman crew member saying they had "trespassed" into Iranian waters.
Britain, which earlier broke all official contacts with Iran except those related to the detained crew, said it feared they may have been coerced into appearing on television. It insisted they had been seized in Iraqi waters.
"It is completely unacceptable to parade our people in this way," British Defense Minister Des Browne said.
After the broadcast, Iran's foreign minister told Reuters London must accept the sailors were arrested in Iranian waters, while repeating an earlier announcement the woman would be freed "as soon as possible."
London said it had no confirmation of any pending release and demanded access to the group, detained at a time of high tension between Iran and Western countries over Tehran's nuclear program.
Shown wearing an Islamic headscarf and speaking calmly, the woman was named by British media as 26-year-old Faye Turney, married with a three-year-old daughter.
A letter, which Iranian officials said she had written to her parents, said: "Hopefully it won't be long until I am home to get ready for Molly's birthday party..."
Al-Alam, a state-run Arabic-language television channel, showed Turney and several of the other sailors in uniform eating off plastic plates in a well-lit room. It also showed a separate interview with Turney, wearing a black headscarf, smoking a cigarette and speaking about her detention and treatment.
"I was arrested on Friday the 23rd of March. Obviously we trespassed into their waters," Turney said in an even voice.
'The lady will be released'
Earlier, the Iranian foreign minister said that his country would free Turney on Wednesday or Thursday.
"Today or tomorrow, the lady will be released," Manouchehr Mottaki said Wednesday on the sidelines of an Arab summit that he was attending in the Saudi capital.
Mottaki discounted the possibility of an escalation in the crisis, suggesting that the alleged entry into Iranian waters may have been a mistake.
"This is a violation that just happened. It could be natural. They did not resist," He said.
Britain on Wednesday released the coordinates where it said the crew was detained by Iranian boats as it searched for smugglers. It said the coordinates proved British claims that they were in Iraqi waters.
Mottaki denied this, saying, "That's not true. It happened in Iranian territorial waters."
UK cuts ties with Iran
Britain said it was freezing talks on all other issues with Iran until it freed 15 Royal Navy crew members seized last week, and the British military released what it said was proof its boats were within Iraqi territorial waters when they were seized.
Britain's military said its vessels were 1.7 nautical miles inside Iraqi waters when Iran seized the sailors and marines on Friday.
Vice Adm. Charles Style told reporters that the Iranians had provided a position on Sunday — a location that he said was in Iraqi waters. By Tuesday, Iranian officials had given a revised position 2 miles east, placing the British inside Iranian waters — a claim he said was not verified by global positioning system coordinates.
"It is hard to understand a legitimate reason for this change of coordinates," Style said.
Style gave the satellite coordinates of the British crew as 29 degrees 50.36 minutes north latitude and 048 degrees 43.08 minutes east longitude, and said it had been confirmed by an Indian-flagged merchant ship boarded by the sailors and marines.
Prime Minister Tony Blair told the House of Commons that "there was no justification whatever ... for their detention, it was completely unacceptable, wrong and illegal."
"We had hoped to see their immediate release; this has not happened. It is now time to ratchet up the diplomatic and international pressure in order to make sure the Iranian government understands its total isolation on this issue," Blair said.
British Foreign Secretary Margaret Beckett said Britain had frozen bilateral talks with Iran on all other issues until Tehran frees the crew.
"No one should be in any doubt about the seriousness with which we regard these events," Beckett told lawmakers.
AP contributed to this report