During the Iran-Iraq war there were extensive rumours in the press regarding Iran’s use of Iranian Military Procurement Offices (IMPOs) in London to purchase arms. This article seeks to interrogate the facts behind these rumours: what was going on inside the IMPOs? How much intelligence did the British government have about this? Not a huge amount – largely a result of the IMPOs being a challenging target and Britain’s intelligence priorities in London lying elsewhere. More broadly the paper seeks to provide insights into the challenges of gathering intelligence from – and responding to the activities of – foreign government targets on home turf, as well as providing insights into an under-considered area of intelligence – that surrounding embargoes and sanctions.