Arfajah (may Allah be pleased with him) says: I prayed the Fajr prayer behind Sayyiduna Ibn Mas'ud (may Allah be pleased with him) and he did not recite qunut, and I prayed behind Sayyiduna Ali (may Allah be pleased with him) and he recited qunut.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصلاة / 3117