[7] In October 2017, the prosecutor general of Tehran made a new claim that Zaghari-Ratcliffe was being held for running "a BBC Persian online journalism course which was aimed at recruiting and training people to spread propaganda against Iran".

[8] Zaghari-Ratcliffe has always denied the spying charges against her, and her husband maintains that his wife "was imprisoned as leverage for a debt owed by the UK over its failure to deliver tanks to Iran in 1979.

On 3 April 2016, members of Iran's Revolutionary Guard arrested her at the Imam Khomeini Airport as she and her daughter were about to board a flight back to the UK.

[19][20] Her daughter's British passport was confiscated during the arrest, but later returned, and she remained in Iran under the care of her maternal grandparents so she could visit her mother.

[22] This is an international charity that provided training courses to Iranian citizen journalists and bloggers in its Iran Media Development Project's ZigZag magazine and associated radio programme.

CEO of the Thomson Reuters Foundation, Monique Villa, said “Nazanin has been working at the Thomson Reuters Foundation for the past four years as a project coordinator in charge of grants applications and training, and had no dealing with Iran in her professional capacity.”[27] In early September 2016, Zaghari-Ratcliffe was sentenced to five years in prison for allegedly plotting to overthrow the Iranian government.

[5][6] The prosecutor general of Tehran stated in October 2017 that she was imprisoned for running "...a BBC Persian online journalism course which was aimed at recruiting and training people to spread propaganda against Iran".

"[30] In March 2019, the British Foreign and Commonwealth Office (FCO) granted Zaghari-Ratcliffe diplomatic protection, raising the status of her case from a consular matter to a dispute between the two governments.

[52] The British government denied this the next day, saying the negotiations about the debt, accrued due to it not delivering tanks to Iran as agreed in a deal made in the 1970s, were separate from her case and still ongoing.

[53] In February 2018, Richard Ratcliffe said he believed his wife's release was dependent on the interest on a £450 million debt the UK has owed to Iran since the 1970s for a cancelled arms deal.

[54][55] In October 2019 he repeated the claim with more detail, stating that a UK government agency was using "every legal roadblock to delay and minimise the payment".

[56] In 1971, the Iranian government, then under the Shah of Iran, paid Britain for an order for more than 1,500 Chieftain tanks and other armoured vehicles as part of a £650 million deal.

[59] In January 2016, the United States refunded Iran $400 million for undelivered military equipment which was associated with the release of four Iranian-Americans, including Washington Post journalist Jason Rezaian, which could be viewed as a precedent for Zaghari-Ratcliffe's situation.

[63]Richard Ratcliffe reaffirmed his belief that his wife was being used as a bargaining chip in the dispute over the unpaid IMS debt and talks over the Joint Comprehensive Plan of Action nuclear enrichment deal with Iran.

[64] The debt repayment deal failed, which Prime Minister Boris Johnson later explained as "difficult to settle and square away for all sorts of reasons to do with sanctions".

[65] On 16 March 2022, Foreign Secretary Liz Truss announced that after months of negotiations the government had paid the debt of £393.8 million to Iran, ring-fenced for humanitarian use only.

[15][14] On 21 March 2022, the House of Commons Foreign Affairs Select Committee announced it would hold an inquiry into the delay in paying the debt to Iran.

[66] On 7 May 2016, Zaghari-Ratcliffe's husband, Richard Ratcliffe, launched an online petition[67] urging both the Prime Minister of the United Kingdom and Iran's supreme leader to take appropriate action to secure the safe return of his wife and daughter.

[69][70] In September 2021 Richard Ratcliffe and the release campaigns called on the British government to sanction individual Iranian officials involved with the detention with asset freezes and travel bans.

[75][76] However, on 1 November 2017, the then-British Foreign Secretary Boris Johnson said "When we look at what Nazanin Zaghari-Ratcliffe was doing, she was simply teaching people journalism, as I understand it, at the very limit.

[85] The call was repeated a year later by Shaheed's successor, Asma Jahangir, as well as by José Antonio Guevara Bermúdez, Chair-Rapporteur of the Working Group on Arbitrary Detention: "We consider that Ms. Zaghari-Ratcliffe has been arbitrarily deprived of her liberty and that her right to a fair trial before an independent and impartial tribunal has been violated … These are flagrant violations of Iran's obligations under international law".

[92] In December 2020, in relation to Zaghari-Ratcliffe's imprisonment it was widely reported that British citizens arrested abroad do not have a right to government help or protection even if they are being tortured.

[98] The decision to release her has been linked to the UK's payment of the £393.8 million debt related to the unfulfilled arms deal in the 1970s,[99] although the Iranian government have denied this,[100] and British Foreign Secretary Liz Truss called them "parallel issues".

[15] Other factors which have been described as contributory included her family's campaigning, British diplomacy's focus on the issue and an alignment of interests between the two countries during the Russian invasion of Ukraine.

[102] Zaghari-Ratcliffe said in a press conference soon after her release that the feeling of returning home was "precious" and "glorious" but also criticised the government's response to her imprisonment commenting that "I have seen five foreign secretaries change over the course of six years.

"[104] Because of the Mahsa Amini protests, Zaghari-Ratcliffe cut her hair publicly as a symbol of opposition to tyranny in the Islamic Republic of Iran.

She told Andy Murray that she had experienced a rare moment of joy during her imprisonment when her captors gave her a television, on which she saw him win the Men's singles at the 2016 Wimbledon Championships.