The Iranian Revolutionary Guard accused a British-Iranian aid worker who has been detained since early April of trying to "overthrow" the government in a statement published on Wednesday.
Nazanin Zaghari-Ratcliffe is a 37-year-old program coordinator with the Thomson Reuters Foundation, a London-based charity.
Iranian Revolutionary Guard officials detained Zaghari-Ratcliffe on April 3 when she arrived at an airport to fly back to Britain, according to her husband Richard Ratcliffe.
"This person had membership in foreign companies and organizations and planned and carried out media and cyber projects with the intent of a soft overthrow of the holy Islamic Republic government," the statement said. It was published by a Guard office in Kerman province, where Zaghari-Ratcliffe is being held.
Zaghari-Ratcliffe "carried out criminal activities with the guidance and protection of media and spy services of foreign governments," according to the statement. She was arrested after "massive intelligence operations" by the Guard.
Richard Ratcliffe dismissed the accusation that Nazanin was trying to bring down the government as "preposterous."