A deal for the UK to sell tanks to Iran was cancelled after the Islamic revolution. The company behind it is owned entirely by the British government - International Military Services. Even today, it may hold the key to Nazanin Zaghari-Ratcliffe\u2019s release.
Presenter: Ceri Thomas \nProducer: Matt Russell \nOriginal music: Tom Kinsella \nA Tortoise Media production for BBC Radio 4