codeigniter HMVC extension model organization

I am developing a portal and using codeigniter with HMVC extension. I have an "admin" module and a "yellowpages" module. Both these modules have a common model eg: "Category_model", and I use it to list down the categories both in the fronten开发者_如何学Pythond(yellowpages) and backend(admin) module.

So my question is, can I place the model in the application/models directory and have it accessed by both the modules, or do I have to copy the model and place each copy inside /modules/admin/models and /modules/yellowpages/models

Resources may be cross loaded between modules. ie: $this->load->model(‘module/model’);

More info here and here