Abstract: A method for producing a filtering material comprising a cellulosic material and a positively charged polyelectrolyte comprising polyvinylamine (PVAm), wherein said method comprises at least the steps of: —providing a stock comprising said cellulosic material comprising cellulose fibers; —adding said polyvinylamine to said stock such that a concentration of PVAm in the stock is in an interval of 0.5-2.0 wt-% of a dry weight of cellulose fibers in polyelectrolyte to said stock, and —allowing said cellulosic material to adsorb said polyvinylamine.