I really cannot tell if I'm being stupid here, but the files im pulling into premier seem to have the sounded embedded? And I can't seem to seperate them. Nor can I remove the audio completely, which is what i need to to. I haven't had this problem with any other media apart from the files coming off the D90.
The D90 AVIs are mono audio; you can see this in the preview area of the Project Panel. If you're dragging them to a sequence, a mono audio track will automatically be added to the sequence for it. If you're inserting or overwriting from the Source Monitor, you'll have to manually add a track.
What do you mean manually add a track?
Wow, turns out I was being stupid. It's incredibly simple, just for anybody who is having the same problem. Theres a tiny button below the source window that says 'drag video only'. The simplest things are the easiest to overlook!