LONDON — Iran’s continued detention of jailed Iranian-British aid worker Nazanin Zaghari-Ratcliffe is unacceptable, British trade minister Liam Fox said on Tuesday, adding that she should be released as soon as possible.

Zaghari-Ratcliffe is serving a five-year jail sentence after being convicted of plotting to overthrow Iran’s clerical establishment, and was brought into court on Saturday accused by a judge of “spreading propaganda against the regime,” the Thomson Reuters Foundation, a charity organisation for which she works, said.

“This is a very very aggressive, unacceptable way to treat a UK citizen,” Fox said on BBC radio.

“This detention is completely unacceptable to the British government, it is completely, in our view, illegal, and she should be released as soon as possible.” Fox had earlier defended foreign secretary Boris Johnson after Johnson last week said that Zaghari-Ratcliffe had been training journalists in Iran, which the Foundation said was incorrect.

The charges against Zaghari-Ratcliffe are denied by her family and the Foundation, a charity organisation that operates independently of Reuters News.