Hazrat Anas radiyallahu anhu reports that, on the day when Makkah was conquered, the Prophet of Allah sallallahu alaihe wasallam wore a helmet when they entered the city. (The Prophet of Allah sallallahu alaihe wasallam removed the helmet after being satisfied that everything was under control). Someone came to the Prophet of Allah sallallahu alaihe wasallam and said, "O' Messenger of Allah, this Ibn Khatl is holding the cover (black cloth) of the Ka'bah." The Prophet of Allah sallallahu alaihe wasallam replied, "Kill him.
English reference: Book 15, Hadith 105
Arabic reference: Book 16, Hadith 112