10 At first sight, it may appear as if their Honours are saying that it is not for the trial judge on a voir dire to determine whether the evidence discloses that there was no possibility of concoction. However, upon close study, I do not think that their Honours are saying any more than if the evidence upon the voir dire establishes that there was a relationship between the witnesses, an opportunity for concoction and a motive to do so, that will be sufficient to rob the evidence of the probative value that it would otherwise have had. However, if the evidence on the voir dire establishes no real possibility of concoction, then it is for the trial judge to determine in the ordinary way whether the evidence is admissible or not. Thus, in a case such as this where, at the relevant times, the majority of the complainants were in the same class at school, an inquiry on the voir dire is necessary, for that fact alone gives rise to a prima facie suspicion that there may have been concoction or other common cause among the witnesses. However, if after hearing all the evidence on the voir dire it is established that there is no motive for concoction, no suggestion that there has been concoction and no other common cause among the witnesses is apparent, the evidence is admissible provided it otherwise has the requisite probative force. As Brennan J (as he then was) and Dawson J point out in Hoch, at 304, for the purpose of determining the admissibility of a confession, the trial judge makes a finding on the voir dire with respect to the voluntariness of the confession. A finding that it was voluntary will make the confession admissible (subject to discretionary exclusion) but that finding does not preclude the jury from subsequently considering whether it was made voluntarily. Brennan and Dawson JJ said, at 303: