Nothing is to be done which creates even a suspicion that there has been an improper interference with the course of justice.

Gordon Hewart (1870-1943) British politician and jurist; Lord Chief Justice of England (1922-1940)

Rex v Sussex Justices, ex parte McCarthy, [1924] 1 KB 256, [1923] EWHC KB 1, [1924] KB 256 (1923-11-09) [unanimous decision]
    (Source)

See also:

• The origins of “Justice must be seen to be done”.
• R v Sussex Justices, ex parte McCarthy - Wikipedia.