The article analyses the relations between different forms of accountability using the response to the Policía Federal Argentina's practice of inventing police proceedings as a case study. In this case, the lack of accountability activity by the agencies of balance was compensated by the creation of an ad hoc agency of oversight. The interaction between the latest and a series of social accountability agents was decisive in establishing accountability. Special attention is paid to the ambivalent role of the media. Using Peruzzotti and Smulovitz' terminology, it is suggested that this ambivalence shows the tension between political accountability and legal accountability. In this sense, and using a wide definition of accountability, evidence presented here seems to show that the interaction between horizontal accountability and social accountability has been effective.