Occasional reports in the literature suggest that biological samples collected and stored for scientific research are sometimes accessed and used for a variety of forensic purposes. However, donors are almost never informed about this possibility. In this paper we argue that the possibility of forensic access may constitute a relevant consideration at least to some potential research subjects in deciding whether to participate in research. We make the suggestion that if some type of forensic access to research collections is likely (...) to be perceived by the subjects as a reason against donating their biological materials, there are good ethical reasons to make this type of access impossible or at least severely restricted. We also provide an ethical argument for the claim that, if a total ban on this type of forensic access cannot be achieved, potential research subjects should be informed about the extent to which this type of forensic access is possible. (shrink)