If there are no presets being applied during import, then it might be necessary for you to reset your camera defaults or create new camera defaults with settings that work for you. Generally speaking, raw images are not imported into Lightroom and remain untouched. There are usually default settings that are applied. Those default settings are camera specific, and can even be serial number and ISO specific as well.
Please make sure that you do not have any preset selected in Apply During Import in the right hand side panel of Import dialog box.
If you already have Develop Setting as None still you are facing the issue, please follow the instructions provided by James Hess.
Please let us know if this helps.