"No, it's fine for now" - no it isn't. You should get rid of him the moment you realize he's doing something sketchy. After all, just because you destroy their spying machine doesn't mean they'll stop. On the contrary, they'll try to dig your secrets out even more. Of course, he doesn't have evil intentions (probably, seeing how this manga has been so far), but he will drag our MC to all kinds of trouble without a doubt. So better get rid of the troublemaker on day 1.