Portraying prisoner Nazanin was emotionally demanding, and a wake-up to her six-year struggle

Marion McMullen learns how Narges Rashidi and Joseph Fiennes got to grips with a real-life couple's terrifying fight for freedom

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Nazanin Zaghari-Ratcliffe was torn from her 22-month-old daughter, arrested, falsely accused of espionage and imprisoned in Iran in 2016.

She had been visiting relatives with her child, Gabriella, and was at the airport for a flight back to the UK at the time of her arrest.

Thousands of miles away, in London, her husband Richard refused to stay silent and started to do everything in his power to bring her home.

The BBC's new factual drama Prisoner 951 is based on their extraordinary true story and tells of how British-Iranian citizen Nazanin was imprisoned and held hostage by the Iranian state for six years.

Gangs Of London actress Narges Rashidi, who plays Nazanin, says: "Emotionally, it was probably the most demanding role I've ever played. We were shooting incredibly intense scenes day after day.