London (CNN) British Foreign Secretary Boris Johnson is facing further pressure after Iranian state TV claimed that his statements on the plight of a British-Iranian woman imprisoned in Tehran on charges of espionage confirmed her guilt.

Johnson has already been forced to correct remarks he made to a British parliamentary committee last week, when he said that Nazanin Zagahri-Ratcliffe, who has been in jail since she was detained at Tehran airport in April 2016, had been teaching journalism during her visit to the country.

After Johnson's original comments, authorities in Iran filed further charges against Zagahri-Ratcliffe, prompting fears her five-year sentence could be extended. On Wednesday, Iranian state TV IRIB said Johnson amounted to an unintentional confession.

Nazanin Zaghari-Ratcliffe is being held in an Iranian prison.

"It seems Boris Johnson's remarks repudiated all the claims that we've seen in the past year and a half from British media and government officials who were saying Nazanine Zaghari-Ratcliffe had come to Iran for humanitarian purposes," IRIB reported.

The IRB report said that Zaghari-Ratcliffe's role with the Thomson Reuters Foundation amounted to working for a "multi-national company established with the aim of promoting Western-style democracy."

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