UNITED NATIONS  —  Iran has published another letter allegedly written by Leading Seaman Faye Turney in which she supposedly calls for British forces to withdraw from Iraq.

The letter also asks the British government why it allowed the British captives to stray into Iranian waters.

• Click here to read the full text of the letter.

And it goes on to say the group is being treated well by the Iranians.

Analysts immediately doubted the validity of the letter, saying the wording was not likely to have been thought up by the 26-year-old sailor.

The letter coincided with the release of new footage of the 15 Royal Navy sailors and Royal Marines being seized by Iranian gunboats in the Gulf.

In the video clips, gunshots are heard and a helicopter is shown hovering above inflatable boats in choppy seas.

Vessels close in on Royal Navy boats then the 15 captured Britons are shown seated in an Iranian gunboat.

The arrest footage was preceded by a senior Iranian officer using maps to explain how the Britons had "crossed into Iranian territory."

But the U.K. has maintained the crews were in Iraqi waters and were wrongfully seized.

Iranian TV had previously shown video footage of the detainees eating and talking.

That broadcast featured an interview with Turney in which she confessed — probably under duress -- that the Britons had been at fault.

Prime Minister Tony Blair said it was a "disgrace" the way Turney, a mother of a three-year-old girl, was shown on TV.

"We are going to have to step up pressure not just with them in the U.N. and the European Union, but see what further measures are necessary to get them to understand it's not merely wrong but only going to result in further tension," he added.