20. (1) A guardian stands in a fiduciary relation to his ward, and, save as provided by the will or other instrument, if any, by which he was appointed, or by this Act, he must not make any profit out of his office. (2) The fiduciary relation of a guardian to his ward extends to and affects purchases by the guardian of the property of the ward, and by the ward of the property of the guardian, immediately or soon after the ward has ceased to be a minor, and generally all transactions between them while the influence of the guardian still lasts or is recent.