Misprision of treason

Misprision of treason is an offense recognized in many common law jurisdictions, inherited from English law, that punishes a person who knows treason is being planned or has been committed and fails to report it to the proper authorities. The offense does not require that the accused took part in or consented to the treason itself; knowledge combined with silence is enough to violate the law. Originally, concealing knowledge of treason was itself treated as treason under English common law, but the Treason Act 1554 downgraded this conduct to misprision of treason, reclassifying it as a felony rather than high treason, a distinction that carries different consequences and procedures to this day. Versions of the offense remain on the books in jurisdictions including Australia, Canada, Hong Kong, Ireland, New Zealand, the United Kingdom and the United States, each with its own statutory wording and penalties, though prosecutions under it are now rare.