This article analyses the decision of the  ICC  Pre-Trial Chamber of 16 July 2015 in which it requested the Prosecutor to reconsider its decision not to initiate an investigation into the situation of the registered vessels of the Union of the Comoros, Greece and Cambodia. In 2010, the Israeli Defense Forces ( IDF ) had intercepted a humanitarian aid flotilla that was trying to breach one of its naval blockades. The Prosecutor deemed the case of insufficient gravity to initiate an investigation. By requesting the Prosecutor to reconsider its decision, the Pre-Trial Chamber created a precedent  vis-a-vis  the boundaries of prosecutorial discretion. This article addresses the test of Article 53(1)  ICC  Statute and inquires whether the Pre-Trial Chamber applied a correct standard of review. Whilst concluding that the Chamber erred in this standard, the authors introduce a standard of review that anticipates the interrelationship between prosecutorial discretion and judicial review.