The "top leadership" of the National Testing Agency is under the scanner over alleged irregularities in competitive exams NEET and NET, Union Education Minister Dharmendra Pradhan said on Saturday even as he denied any paper leak in the CSIR-UGC NET, which was postponed a day back. The minister said he is the custodian of students' interests and has to take that into account before taking any step. Amid a raging row over irregularities in the medical entrance exam NEET, Pradhan had said earlier this week that he cannot jeopardise the careers of the lakhs of candidates who cleared the exam rightfully. The June edition of the Joint Council of Scientific and Industrial Research and UGC-NET was postponed on Friday night. The Joint CSIR-UGC-NET is a test conducted to determine eligibility for junior research fellowship and assistant professor and admission to PhD in science courses. "There was no leak in CSIR-UGC NET, it was postponed because of logistic issues. There is also a retest of