Wills Act 1968

If a testator, by will, charges real property or personal property with payment of a debt due to a creditor and the creditor, or the domestic partner of the creditor, attests the signing of the will or the acknowledgment of the signing of the will, the creditor or domestic partner, as the case may be, is not, by reason of that charge, disqualified from being admitted as a witness to prove the execution, or the validity or invalidity, of the will.