Royal Commissions Act 1923

Any person who, knowing that any document or other thing is or may be required in evidence before a commission, wilfully destroys it or renders it incapable of identification or, in the case of a document, renders it illegible or undecipherable, with intent thereby to prevent it from being used in evidence, shall be guilty of an indictable offence, and shall be liable to be imprisoned for a period not exceeding two years.