Some parts of the paper were leaked on WhatsApp & we've made Police complaint regarding it. Investigation is underway & strict action will be taken. We have also decided to tighten security for the time when papers are being distributed: HRD Minister on X, XII CBSE paper leak. PM Narendra Modi spoke to HRD Minister Prakash Javadekar and conveyed his unhappiness over the paper leak issue, asked for strict action: Sources