UK Foreign Secretary Boris Johnson has been urged to correct his statement on the detention of British citizen Nazanin Zaghari-Ratcliffe, who was arrested in Iran in 2016 on accusations of plotting to overthrow the regime.

The British-Iranian mother from London was detained by Iran's Revolutionary Guard last April as she attempted to return to the UK following a family vacation. She was sentenced to five years in prison. Although she is accused of leading a "soft coup", charges against her have not been fully disclosed.

Johnson told a parliamentary committee earlier in November that Zaghari-Ratcliffe, a 38-year-old charity worker and a project manager with Thomson Reuters Foundation, was "simply teaching people journalism" in Iran.

The Foreign Secretary condemned her arrest and Tehran's treatment of the woman, calling her conviction a "mockery of justice".

Although his speech was welcomed, Johnson was criticised for incorrectly stating that Zaghari-Ratcliffe was working, a claim that some fear could increase chances of her detention to be prolonged.

Zaghari-Ratcliffe, who maintains her innocence, lost her appeal against the sentencing in April.

She was summoned to court last week, where Johnson's comments were used as new evidence of what the woman was doing in Iran at the time of her arrest. She was accused of engaging in "propaganda against the regime" and could face an addition five-year sentence.

"On 1 November, he [Johnson] said that that Nazanin 'was training journalists in Iran'. I have immediately clarified that this is not right as she is not a journalist and has never trained journalists at the Thomson Reuters Foundation where she is a project manager in my media development team," Monique Villa, CEO of Thomson Reuters Foundation, said in statement.

"She was in Iran on holiday to show her daughter Gabriella to her grandparents when she was arrested at Tehran Airport on 3 April 2016. Like Richard Ratcliffe, her husband, I see a direct correlation between this statement by Boris Johnson, who rightly condemned the treatment that Nazanin has received in Iran, and the fact that Nazanin was brought once again into court on Saturday November 4 and accused of 'spreading propaganda against the regime."

Iran's High Council for Human Rights said Johnson's remarks showed that "Nazanin had visited the country for anything but a holiday".

"For months it was claimed that Nazanin is a British-Iranian charity worker who went to see her family when she was arrested," the council continued.

"Mr Johnson's statement has shed new light on the realities about Nazanin, which has been strongly denied previously by both her family and Human Right activists such as Shirin Ebadi."

Zaghari-Ratcliffe's husband, Richard, told The Times: "[Mr Johnson's] misstep saying she was training journalists not that she was on holiday - contradicting what we have said all along – is being used for propaganda purposes to justify holding her."

Rights group Amnesty International expressed similar fears. In a statement sent to IBTimes UK, Allan Hogarth, Amnesty UK's head of policy and government affairs, said: "The Foreign Secretary's call last week for Zaghari-Ratcliffe to be released was welcome, but he must clarify his remarks about her work and the purpose of her visit to Iran last year.

"It's important that the UK Government keeps insisting on the fact that Zaghari-Ratcliffe is a charity worker, and that she should be released immediately and allowed to return back to Britain with her daughter Gabriella."

Both Richard and human rights groups have claimed conditions of Zaghari-Ratcliffe's detention amount to torture. Nazanin spent 18 months in solitary confinement, without medical assistance or contact with her family.

A spokesperson for the Foreign Office told IBTimes UK Johnson's remarks have no "justifiable basis" for additional charges against Zaghari-Ratcliffe.

Nazanin Zaghari-Ratcliffe
Family of imprisoned Nazanin Zaghari-Ratcliffe, seen with her daughter, have protested her innocence Family handout/PA