what I see as strange with this problem is that if it is a employee that sells or try to get traffic to another site for one or another reason, why would they go for inactive accounts, it is not like getting a signup is worth something.
I would understand if a test account was made and £1000 was deposited, then that player would get some attention, but why steal and risk getting caught for a no deposit client?
So either some kind of spyware on the guys testing this, but on the other hand if two affiliates tested it and got the same it sounds very strange indeed.
So more likely a common practice with the original company to transfer players, cause they would not have time or energy to go in and manually check each individual account, which for instance a CS agent would have time to do.
Just my thoughts