What sort of camera do you have? If its an SLR its possible, though it may just be in or on the prism/mirror. If its a rangefinder, it may be annoying but it won't affect the picture as the viewfinder and the lens don't "see" the same thing.
If it's an SLR, remove the lens and look into the mirror/prism and see if you can see anything. If you don't have any film in the camera with the lens off set the shutter to "B" (for bulb) it will keep the mirror up and the shutter open as long as you hold down the shutter release. If you see the debris here, then you might have a problem. You might also be able to identify what it is.
Joel.