Hilchos Lashon Hara chapter 7, section 14

From this you can see how many people make mistakes in these matters. If something was stolen from them and they suspect someone, they tell the town leaders that they have clear signs against him. Then the leaders hit and punish him, against halacha, so that he will admit.

This is wrong, because real clear signs or witnesses are needed. One cannot rely on the person who is complaining and hit a Jew for nothing just because they suspect him. Even just believing in one's heart the one who is complaining, that this man stole from him, is forbidden because it is accepting lashon hara. And all the more so it is forbidden to hit him, because that breaks the negative commandment "He shall not add" (to the lashes).