The Political-Social Brigade (Spanish: Brigada Político-Social, BPS), officially the Social Investigation Brigade (Spanish: Brigada de Investigación Social, BSI), was a secret police in Francoist Spain in charge of persecuting and repressing opposition movements. The brigade was a section of the General Police Corps (CGP). During the Spanish transition to democracy, it was restructured and replaced by the (BCI). Among the anti-Franco opposition, it was known colloquially as "the Social", "the Secret" or "the Brigade".