Nazanin Zaghari-Ratcliffe 'upset' in Tehran jail
Prof Homa Hoodfar is a dual national Canadian Iranian who was held by Iranian intelligence and detained for over 100 days at Tehran's Evin prison earlier this year.
During her time in prison she spent one night with the British-Iranian captive Nazanin Zaghari-Ratcliffe who remains in custody.
Thomson Reuters charity worker Mrs Zaghari-Ratcliffe, from London, was arrested on April 3 as she tried to fly home after visiting family in Iran.
In September she was sentenced to five years in jail on undisclosed charges.
Campaigners are due to take part in a protest demanding the British Government do more to secure her release.
Prof Hoodfar tells Stephen Sackur that Mrs Zaghari-Ratcliffe was upset and missing her young daughter Gabriella.
Hoodfar: How I survived prison in Tehran
You can see the interview in full on BBC World News and the BBC News Channel and after on BBC iPlayer (UK only)