The number of cases involving quasi-legal drugs that authorities took action against in the first half of 2015 rose to 633, nearly five times more than the 127 reported in the same period the previous year, a police report showed Thursday.
The preliminary report by the National Police Agency also said the police began investigating most cases last year and only 169 cases, or about 26.9 percent, were new, signaling "the pace of fresh detection has been falling as a result of enhanced crackdowns," according to an NPA official.
The cases involve drugs chemically resembling or having similar effects to illegal narcotics, such as stimulants and marijuana or regulated drugs, as well as those containing quasi-legal or illegal substances while claiming they do not.