LONDON (Reuters) - The British government summoned the Iranian ambassador on Thursday following news that imprisoned British-Iranian aid worker Nazanin Zaghari-Ratcliffe is to be recalled to court in Iran, the Foreign Office said. The British authorities conveyed their grave concern to the diplomat, Hamid Baeidinejad, and called for Iran to end what they described as Zaghari-Ratcliffe’s arbitrary detention.“We have made it clear to the Iranian ambassador that his country’s treatment of Nazanin Zaghari-Ratcliffe is unjustified and unacceptable, and is causing an enormous amount of distress,” the Foreign Office said in a statement. A project manager with the Thomson Reuters Foundation, the dual national was arrested in April 2016 at a Tehran airport as she prepared to head back to Britain with her daughter after a family visit.