"The Foreign Secretary expressed concern at the suggestion from the Iranian Judiciary High Council for Human Rights that his remarks last week at the Foreign Affairs Committee'shed new light' on the case," the Foreign Office said in a statement. "The Foreign Secretary said this was absolutely not true. It was clear, as it always had been, that Mrs. Zaghari-Ratcliffe had been in Iran on holiday when arrested."
The figure had been a central part of the Johnson and the Leave campaign's "let's take back control" message, with suggestions that the money could instead be used to fund state healthcare, although that pledge was quickly abandoned by other prominent campaigners immediately after they won the referendum.
Oman, a Gulf Arab country on the southeastern tip of the Arabian Peninsula, is a U.S. ally and has been ruled by Sultan Qaboos bin Said since 1970. It has served as a mediator between Iran and the West to secure prisoner releases in the past. In 2013, it hosted the secret talks between Iran and the U.S. that later led to the 2015 nuclear deal between Iran and world powers.