On 23 March 2007, fifteen Royal Navy personnel from HMS Cornwall were searching a merchant vessel when they were surrounded by the Navy of the Iranian Revolutionary Guards and detained off the Iran–Iraq coast. In the course of events, British forces claimed that the vessel was in Iraqi waters, but the Iranians insisted that they were in Iran's territorial waters. The fifteen personnel were released thirteen days later on 4 April 2007.
A year later, a British investigation report was released which stated that the area in which the incident took place was not covered by any formal agreement between Iran and Iraq.