A fishing sinker includes a sinker body with a bore formed through it. A unidirectionally displaceable insert is received in the bore with a passage for line formed through the insert. A friction reducing sleeve is located between the bore and the insert and is fast with the sinker body. The insert is unidirectionally displaceable by virtue of it having an enlarged head that is incapable of proceeding through a narrow elongate portion of the sinker bore. Consequently the insert can only egress from the sinker in one direction. The sinker is designed to make it difficult for fish to feel any jerking or hesitation on the line as they take a baited hook so that they are not immediately alerted to the presence of fishing tackle.