as an attorney from the US it is difficult to answer as to how to obtain information from a person in Canada. What I would suggest trying to do is finding out where your husband resides and contacting an attorney who works in that area.I am sure they have similar laws to those that we have and the attorney can make a motion that requests your husbands financial records if he is in fact hiding income. You can request to re argue the settlement amount if he is working and it was done as if her weren't. But not being an attorney trained in Canada all this is an assumption and short of a PI as you suggested you will have to contact a Canadian lawyer who can inform you of the procedures in that area