Specific binding members directed to human glycoprotein VI (GPVI), in particular human antibodies, may employ the antibody VH and/or VL domain of the scFv fragment herein termed 10B12 or one or more complementarity determining regions (CDRs) of the 10B12 heavy chain variable (VH) and/or light chain variable (VL) domains, especially VH CDR3 in other antibody framework regions. Antibody molecules are provided with advantageous and unexpected properties, especially ability to inhibit collagen-induced platelet aggregation and the adhesion of platelets to Collagen-Related Peptide (CRP). Domain 1 of human GPVI is a primary target for the 10B12 antibody with these properties, and the epitope includes lysine 59.