Police on Tuesday said they were looking into debt collection posters with HK$10 notes attached that were discovered scattered around Sheung Wan.
A video put online shows people picking up the posters, which threatened that the debtor would "reach a dead end" if the money isn't repaid.
Police said a man handed in more than 80 such posters on Monday, saying he had picked them up from Des Voeux Road near Wing On Centre.
Officers have classified the matter as a “request for police assistance”.