Abstract: Apparatus for downhole filtration of fluids in a wellbore. The apparatus has a diverter and a filter slidably mounted on a mandrel. The diverter has a circumferential wiper element between the mandrel and the casing within which the apparatus is run. When fluids are reverse circulated, or the tool is being pulled out, the diverter shifts to a downward position, wherein it seals against an upper end of the filter, filtering out solids in the fluids and retaining them in a chamber between the sleeve and mandrel. When running the tool into a wellbore, the diverter shifts to an upper position to permit fluids to bypass the filter sleeve. The filter sleeve bears against a spring loaded seat, which permits creating a gap between the diverter and an upper end of the filter sleeve to allow fluids to bypass the filter sleeve should the filter sleeve slots become plugged.