It is narrated from Sayyiduna Abu Qatadah (may Allah be pleased with him): When it was the day of Hunayn (and he related the hadith about his killing a man), he said: I went to the Messenger of Allah (peace and blessings be upon him) and heard him say: "Whoever has proof over a captive, his spoils are his."
The hadith masters (huffaz) regard this as a mistake. (In the narration of al-Layth) it is: "Whoever has proof over a slain man, his spoils are his," and (in the narration of Malik) it is: "Whoever kills a man and has proof of it, his spoils (salab) are his." No one said "over a captive" in it except Hushaym.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب قسم الفيء والغنيمة / 12859