Abstract: The invention provides a marker projectile a hollow body (4) having an opening at the front; a marker substance (3) disposed within the hollow body (4); and an expelling member (5) within the hollow body (4) behind the marking substance (3); the hollow body (4) and expelling member (5) being configured such that upon impact of the projectile with a target, the momentum of the expelling member (5) relative to the hollow body (4) carries the expelling member (5) forwardly to expel the marking substance (3) through the opening, a separator (1) extending at least partly over the front opening, the separator (1) defining two or more spaces through which the marker substance (3) may pass when expelled through the opening and characterized by a deformable closing member (2) positioned between the marking substance (3) and the separator (1), the closing member (2) configured to deform under the impact of the travelling expelling member (5) whereby to release the marking substance (3) from the hollow body (4).