Newly-elected Dundee University rector Craig Murray has defended his claims that the 15 British sailors and Royal Marines being held in Iran may have been trespassing.

The former British ambassador to Iran’s regional neighbour Uzbekistan, an outspoken critic of the war on terror, ignited a media-storm last week with claims on his blog that there is no agreed maritime boundary between Iraq and Iran in the Persian Gulf.

Mr Murray reckons Iran may have a legitimate claim on the co-ordinates of the incident, published by the British Government last week to support its assertion that the sailors were in Iraqi waters when apprehended.

“The Iran/Iraq maritime boundary shown on the British government map does not exist. It has been drawn up by the British Government,” Mr Murray said.

He said only Iraq and Iran can agree their bilateral boundary, and they have never done this in the Gulf, only inside the Shatt-al-Arab waterway “because there it is the land border, too.”

He calls the published boundary “a fake with no legal force,” and says the vessel carrying the 15 prisoners was closer to Iranian land than Iraqi land.

Mr Murray claims that his doubts over the boundary are being taken seriously by Whitehall, and may be used as a bargaining tool to get the prisoners back.

He added, “At a working level, Whitehall is trying to get reality back into the British position, though this may get stomped on again by the spin doctors.

“One of my many friends within the FCO (Foreign and Commonwealth Office) has seen minutes between officials discussing ‘Craig Murray’s points’ on the border question and whether admitting the border is unclear could be a path to getting our people back.”

Mr Murray, who headed the maritime section of the Foreign and Commonwealth Office from 1989 to 1992, has challenged his former employers to make these minutes public under Freedom of Information legislation.

An FCO spokeswoman said, “Our stated position is as it has always been: that the British prisoners were in Iraqi waters when they were picked up.

“Mr Murray is entitled to his opinion on the matter and I have seen the comments he has made, but I see little point in discussing them any further as they contradict our stated position.”

The spokeswoman said if Mr Murray wished to obtain a copy of the minutes in which he alleges his points are being taken seriously, he would have to do so through an FOI request.”