Two SAS soldiers on a secret mission were captured by Syrian authorities after straying across the border from Iraq, it emerged yesterday.
They were released only after a "high-level intervention" by the British Government - believed to involve a visit by Foreign Office Minister Mike O'Brien to the Syrian capital Damascus two weeks ago.
Last night, the Ministry of Defence refused to comment publicly on the embarrassing incident, but senior officials confirmed privately that members of the elite 22 SAS Regiment were involved.
Allied relations with Syria have deteriorated sharply during the war in Iraq.
America has branded the country a "rogue state" and accused Damascus of harbouring senior Iraqi figures, prompting fears of allied military strikes.
Although Syria bitterly opposed the invasion of Iraq, it agreed to release the SAS men unharmed.
Sources close to the Hereford-based regiment last night said the men had been setting up a classic Special Forces ambush to catch senior Iraqi figures seeking sanctuary in Syria.
An insider said: "The team was operating on a remote road into Syria. Two men were watching from a concealed position, and the two who were captured were waiting down the road to stop or ambush vehicles that looked promising.
"They were actually inside Syria, but they knew that. It wasn't a mistake. They chose the best spot and they knew there was a risk of being compromised and captured by the Syrians.
"They were under orders not to get into a firefight if that happened, as we weren't at war with Syria. Unfortunately, they were caught, but they followed orders and didn't resist. They're back safe and, frankly, that's all we're worried about."
British and American Special Forces were heavily involved in "screening" the border between Iraq and Syria to prevent Iraqi leaders fleeing to safety, as well as scouring the deserts of western Iraq for Scud missiles, and gathering intelligence on military sites across the country.
In a separate incident, two other members of Britain's Special Forces came close to being captured by the Iraqis. Insiders have blamed faulty American intelligence, which almost caused a disaster.
They say the two men were part of a covert patrol probing Iraqi defences around the northern city of Mosul, but found themselves surrounded by Iraqi units, despite US intelligence claims that their drop zone was clear of enemy troops.
They were cut off and managed to evade capture for three days, before finally being rescued by helicopter.
The Ministry of Defence was forced to admit to the incident when a captured military Land Rover was shown on television screens around the world.
The MoD said last night that there were no members of the British forces missing in Iraq.
Of the 32 fatalities, only one body had not been recovered - that of 26-year-old Royal Navy Lieutenant Marc Lawrence, who died in a helicopter collision at sea on March 22.