Are surreptitious recordings admissible in a custody dispute?

The parties referred me to a number of cases discussing whether surreptitious recordings are admissible. I was given cases on both sides of the issue, but in the British Columbia cases I was given, most cite and rely on Barrow J.’s discussion in Mathews v. Mathews, 2007 BCSC 1825. In that case, which involved recording information concerning a child’s best interest in a custody dispute, he stated (para. 43) that, “it is clear there is a limited discretion to exclude relevant evidence in this context”, and that “judicial exercise of that discretion involves a balancing of competing interest which can be usefully viewed as assessing the probative value of the evidence as against its prejudicial effect”.