i have a theory. Remember when Conan, Ai and Agasa went to find information about Ai's parents? The time when they found audiotape Ai's sister had hidden in the toilet?
That house was was owned by Atsushi Miyano, Ai's father! And there was still a tenant there. So either way Atsushi is alive or one of the three people in the house is part of the organisation. If we think it is one of those three, i think we can forget Tetsuo Imai because he was arrestet. So i think it's either Isamu Natsuhori or Ukihito Zaitsu. And Miyano's minus Ai has been there before, why would they go there if they are renting the house to someone. Because the boss is in there!
Okay... That was my theory. It's based on a feeling so i don't know if it could be possible, but it think it is.