Amr bin Shu'ayb narrates from his father, and he from his grandfather (may Allah be pleased with him), that he said: I heard the Messenger of Allah (peace and blessings be upon him) saying on the day of the Conquest of Makkah: "The defendant has more right to the oath, unless proof is established against him."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الدعوى والبينات / 21221