A charity says British Foreign Secretary Boris Johnson may have left a British-Iranian woman facing more prison time with an inaccurate statement about why she was in Iran.

Nazanin Zaghari-Ratcliffe is serving a five-year sentence for plotting the "soft toppling" of Iran's government.

Johnson told a parliamentary committee last week that Zaghari-Ratcliffe was "teaching people journalism" when she was arrested last year.

Zaghari-Ratcliffe's employer, Thomson Reuters Foundation, said Monday that she was taking her toddler daughter to visit relatives.

Chief executive Monique Villa urged Johnson to correct his "serious mistake," saying it "can only worsen her sentence."

The Iranian judiciary's High Council for Human Rights said Johnson's comments proved Zaghari-Ratcliffe "had visited the country for anything but a holiday."

Thomson Reuters Foundation is the charitable arm of the news agency.