A British-Iranian mother jailed in Tehran has lost a final appeal over her conviction for allegedly plotting to topple the government.

Nazanin Zaghari-Ratcliffe, 38, was arrested at Tehran Airport on 3 April last year as she attempted to return to the UK following a holiday with her two-year-old daughter.

Mrs Zaghari-Ratcliffe's daughter Gabriella remains in Iran with family after her passport was seized.

Iran does not recognise dual nationalities, and those detained cannot receive consular assistance.