Michael Gove appeared to leave doubt over the actions of a British woman jailed in Iran after saying he did not know why she was in the country.
In a staunch defence of Boris Johnson, who has been criticised for making remarks that were seized on by Tehran to justify its threats to extend the sentence of Nazanin Zaghari-Ratcliffe, Mr Gove attacked attempts to shift the blame from "who is really at fault".
The country's state TV broadcaster has claimed the Foreign Secretary's suggestion that the mother of one from Fleet in Hampshire was "training journalists" in Iran at the time of her arrest last year amounted to an "unintended admission" of her guilt.
Asked what Mrs Zaghari-Ratcliffe was doing in Iran, Mr Gove told BBC One's The Andrew Marr Show: "I don't know.
"One of the things I want to stress is there is no reason why Nazanin Zaghari-Ratcliffe should be in prison in Iran so far as any of us know."
The Environment Secretary warned it would be a "big mistake" to focus attention on his Cabinet colleague when Iran is "in the dock".
But many have seized upon his remarks as at best unhelpful and at worst, politically cynical.
Meanwhile Nazanin's husband Richard Ratcliffe is repeating his calls to meet with Boris Johnson in the hope of travelling to Iran together to help his wife's case.