Theres a few things that it could be. The sway bar would be the first place I'd check. Theres bushings on each end of the sway bar where it connects to the frame and often these bushings can be worn out or missing completely.
Another issue you could be having is with the front struts. Depending on the type of terrain you drive on daily, your front struts should be changed every 70,000 to 110,000 kms. Easy to test out the struts, simply push down on the front end of the car and watch to see how it recovers. Generally if there is any bounce when the car recovers, your struts are worn out and should be changed. Always change both front struts at the same time.
If you change the struts at home, make sure you mark, either with a punch or marker, your wheel alignment before removing either strut. If you do not mark the wheel alignment, your camber will be out after installation. If you take it to a shop, make it a point to ask them if they provide a wheel alignment as part of the installation process, or if they don't, make sure that you ask them to at least check alignment after installation.