Nazanin Zaghari-Ratcliffe has told the BBC that Iran forced her to sign a false confession before allowing her to fly home to the UK.
She was freed in March, along with fellow British-Iranian national Anoosheh Ashoori, six years after being arrested on spying charges.
What has Nazanin Zaghari-Ratcliffe said?
Mrs Zaghari-Ratcliffe said the Iranian authorities would not let her board her plane home until she had signed the last-minute false confession. A UK official was with her when she signed the statement "under duress", she told the BBC.
The former political prisoner said she wanted to make sure people knew she had been forced to sign, to prevent the Iranian regime from exploiting her "dehumanising" confession.
Who is Nazanin Zaghari-Ratcliffe?
Ms Zaghari-Ratcliffe was detained in Iran while visiting the country with her daughter Gabriella in 2016.
Before her arrest, she lived in London with her daughter and husband.
She worked as a project manager for the charity Thomson Reuters Foundation and had been previously employed by BBC Media Action, an international development charity.