title: Jailed British-Iranian charity worker received letter from ex-UK PM Cameron: prosecutor
text: BEIRUT (Reuters) - A British-Iranian charity worker serving a jail sentence in Tehran received a letter from ex-prime minister David Cameron that showed she had ties to the British government, a prosecutor said on Tuesday, according to Mizan, the news site of the Iranian judiciary. Nazanin Zaghari-Ratcliffe, a project manager with the Thomson Reuters Foundation, a charity organization, is serving a five-year jail sentence after being convicted of plotting to overthrow Iran s clerical establishment. The prosecutor, Abbas Jafari Dolatabadi, said the letter demonstrated Zaghari-Ratcliffe s importance to the British authorities but he did not say when it was sent or provide any other details about it. A spokeswoman at the British Foreign Office said she was not immediately able to comment on whether Cameron had written a letter, but confirmed that both he and his successor, Theresa May, had raised the Zaghari-Ratcliffe case with Iranian authorities.  We will continue to raise all our dual national detainees, including Mrs Zaghari-Ratcliffe s case, with the Iranian government at every available opportunity,  she added. Zaghari-Ratcliffe was arrested by the elite Revolutionary Guards in April 2016 at a Tehran airport, as she was about to return to Britain with her two-year-old daughter after a family visit. Her family and the Thomson Reuters Foundation have both denied the charges against her. Thomson Reuters is a charity organization that is independent of Thomson Reuters and operates independently of Reuters News. Last week her family said Iranian authorities had opened a new case against Zaghari-Ratcliffe, leveling charges that could carry a sentence of 16 additional years in prison. The new charges include joining and receiving money from organizations working to overthrow the Islamic Republic, and attending a demonstration outside the Iranian Embassy in London, the family said. The Foreign Office spokeswoman referred Reuters to a statement it issued last week in which it  expressed concern  that Zaghari-Ratcliffe was facing additional charges and said it was seeking more information from the Iranian authorities. On Tuesday Jafari Dolatabadi also said Zaghari-Ratcliffe was responsible for teaching online journalism for the BBC Persian language service  with the goal of attracting and teaching individuals for propaganda operations against Iran , Mizan reported. Francesca Unsworth, director of the BBC World Service Group, said earlier this year that Zaghari-Ratcliffe had never worked for the BBC s Persian service. 