Dual British-Iranian citizen Nazanin Zaghari-Ratcliffe, jailed for five years in Iran on spying charges, will face a new trial in the coming days. Her sentence was to expire next April but she has been hit with new charges that have not been made public. The charity worker and her young daughter were detained at Tehran’s airport in 2016 after visiting her family. She strongly denies all the charges against her. As Henry Ridgwell reports, her family believes she is being used as a bargaining chip in a dispute over payment for tanks purchased before the Iranian Revolution but never delivered.