Upvote:1
I suppose you are refering to some document or something equivalent.
The code of canon law, about "The Nature and Trustworthiness of Documents" in its numbers 1540 to 1543, but specially the last one, states that if a "document is otherwise defective, it is for the judge to decide what value, if any, must be afforded them.", but I have not found reference about how the documents should be obtained to be valid.
But is my opinion, that must be obvious and your conscience must be clearly convinced, that the information you obtained is true and you had the right to know it.