pvp help

Okay so i was pvping a couple days ago on a pvp server, and i was greatly accused of using mods for they had thought i was hitting them from 4 to 5 blocks away. The guy later reported me saying i cheated and was using mods. Now the admins and Mods are watching me and just recently kicked me with a message saying "Stop cheating and using mods or banned". The guy and i were just pvping with our fists and no armour. My question is how far is the longest distance to hit somebody in minecraft? i searched for it, but could not find the average hitting distance. So if anyone knows please comment and if you have proof from a website please post it!!

ps. i was kicking this guys ass and i think he just reported me for his sake of not looking bad.