§ 261. Subpoena on application for executive clemency. The governor shall have the power in any matter pertaining to an application for clemency, to issue a subpoena to compel the attendance of a person before him at a time and place designated in said subpoena; and he shall also have the power to compel the production of any book, paper or writing by a subpoena duces tecum, directed to a person in whose custody either may be, at a time and place designated in said subpoena. But the provisions of this article shall not apply to any book, paper or writing filed in any office of record in any civil division of this state.