Locke v Locke

The parties to this appeal were the petitioner, Thelma Phyllis Lorraine Locke, and the respondent, Terry James Locke, who was her husband. The dispute concerned a petition for the dissolution of marriage filed by Mrs. Locke in the Supreme Court of New South Wales, alleging adultery by Mr. Locke with one Gloria Armstrong. The High Court of Australia heard the appeal from the decision of the Supreme Court.

The legal issues before the High Court were whether the trial judge had erred in law in his approach to determining the issue of adultery, and whether, on the totality of the evidence, the conclusion that adultery had occurred was sufficiently safe. Specifically, the court had to consider the standard of proof required for adultery, particularly in circumstances where medical evidence indicated the intervener was "virgo intacta," and how such evidence should be weighed against other evidence suggesting adultery.

The High Court held that to constitute adultery for the purposes of divorce, some degree of penetration must be proven, though a complete act of intercourse is not necessary. The court emphasised that the actual commission of adultery must be proved affirmatively to the reasonable satisfaction of the court, and this satisfaction should not be achieved through inexact proofs or indirect inferences. Crucially, where medical evidence shows the intervener to be "virgo intacta," this fact must be weighed with all other evidence, rather than being treated as a presumption of adultery to be rebutted. The trial judge's approach of first inferring adultery and then considering the virginity evidence as a rebuttal was found to be legally flawed.

The High Court allowed the appeal, finding that on the whole evidence, an affirmative inference of penetration could not be reached with the requisite degree of judicial satisfaction. Consequently, the decree nisi for dissolution of marriage was discharged, and the petition was dismissed. The costs of the suit were ordered to be paid by the respondent husband, and the costs of the appeal were ordered to be paid by the appellant husband.