Moura Budberg

Maria Ignatievna von Budberg-Bönninghausen (, ''Maria (Moura) Ignatievna Zakrevskaya-Benckendorff-Budberg'', née Zakrevskaya; February 1892 – 1 November 1974), also known as Countess von Benckendorff and Baroness von Budberg, was a Russian adventuress and suspected double agent of the Soviet Union secret police (OGPU) and the British Intelligence Service.

According to the British journalist Robin Bruce Lockhart, who knew her personally, "she was, perhaps, the Soviet Union's most effective agent-of-influence ever to appear on London's political and intellectual stage". Provided by Wikipedia