The family of a UK servicewoman being held in Iran have spoken of the "very distressing time" they are suffering.
The 15 are based on HMS Cornwall, which patrols Iraqi territorial waters
Faye Turney, 26, was the only woman among 15 Royal Navy personnel seized in the northern Gulf on Friday.
In a statement issued via the Ministry of Defence, her family said they were grateful for the support they had received from everyone involved.
The BBC has been told the Britons are being held at an Iranian Revolutionary Guards Corps base in Tehran.
The family statement said: "While we understand the media interest in the ongoing incident involving Faye, this remains a very distressing time for us and our family.
"We are grateful for the support shown to us by all personnel involved and appreciate it, but would request that our privacy is respected."
The MoD has not named any of the eight sailors and seven marines, who were on board HMS Cornwall, which patrols Iraqi territorial waters.
Iran says the Britons were trespassing in Iranian waters, which the UK denies.
An Iranian source told BBC security correspondent Frank Gardner the Britons were being interrogated to find out if their mission was intelligence-gathering.
The source said the investigation involved examining tracking equipment to determine exactly where the crew was captured.
In order for the Britons to be released "every vested interest in Iran would need to be satisfied they had not deliberately entered Iranian waters, nor were they spying", the source added.
Iran has told the Foreign Office that the seized personnel are fit and well.
Previously, the Iranians told the UK's ambassador in Tehran, Geoffrey Adams, that the Britons were being held in Iran but would not disclose their exact location.
Iran says the Britons could be charged with illegally entering Iranian waters, although both Iraq and the UK insist they were in an Iraqi area.
Mr Adams was assured that the eight sailors and seven marines were well during an hour-long meeting on Monday with Ebrahim Rahimpour, a senior official at the Iranian foreign ministry in Tehran.
Mr Rahimpour agreed to stay in close touch with the British embassy but declined to say what plans Iran had for their release, according to a statement from the Foreign Office.
Tony Blair said the UK was "utterly confident" the naval personnel were in Iraqi waters and repeated his call for their release.
Defence Secretary Des Browne later told the Commons the government was doing "everything possible" to secure the release of the detainees.
Shadow defence secretary Liam Fox said the Conservatives wanted MPs to have a chance to discuss the issue as soon as diplomatic sensitivities allowed.
Iraq's foreign minister Hoshiyar Zebari has told his Iranian counterpart Manouchehr Motakki the Britons had been in Iraqi waters when captured.
The group were seized at gunpoint after inspecting an Iraqi boat and returning to their two small boats to head back to the Cornwall.
Students belonging to the paramilitary Basij group, which is close to Iranian President Mahmoud Ahmadinejad, have called for them to be put on trial.