Are We Getting Scammed by Affiliates??

I work for a company that does some affiliate marketing and think someone may be trying to scam us and/or our affiliate (shocker, right?). Here's the deal.....Affiliate #1 has their pixel piggybacked onto ours for an offer and they show A LOT of leads in their system. In our tracking system we show NONE for that affiliate. They sent us an IP list of the transactions that occurred in their system for this offer and I looked to see if transactions occurred in our system under those same IP's....a majority of the IP's they sent are showing up in our system but under a different affiliate. And this is isolated to just this affiliate, out of a hundred or so, so it's not an issue with our tracking system. Is it possible for a sub-affiliate to work with Affiliate #1 and Affiliate #2 to get the same landing page link and then trick their systems into making it appear transactions occurred for both? Our system's cookie overrides past cookies so only one of our affiliates will get credit for a lead. Does anyone have thoughts on how a sub-affiliate is able to do this?