126Loss of client legal privilege—related communications and documents

126 Loss of client legal privilege—related communications and documents If, because of the application of section 121, 122, 123, 124 or 125, this Division does not prevent the adducing of evidence of a communication or the contents of a document, those sections do not prevent the adducing of evidence of another communication or document if it is reasonably necessary to enable a proper understanding of the communication or document. A lawyer advises his client to understate her income for the previous year to evade taxation because of her potential tax liability "as set out in my previous letter to you dated 11 August 1994". In proceedings against the taxpayer for tax evasion, evidence of the contents of the letter dated 11 August 1994 may be admissible (even if that letter would otherwise be privileged) to enable a proper understanding of the second letter.