Police in South Korea questioned two K-pop stars and two other singers resigned on Thursday, as accusations of sex tapes, prostitutes and secret chat about rape rocked the music industry and hit entertainment stocks.

The blame game triggered by accusations against the boyish stars who epitomize an industry that carried South Korean pop culture to the global stage is rooted in concerns the business has neglected morality in its lust for fame and fortune.

Singer Lee Seung-hyun, 28, better known by the stage name Seungri, is suspected of paying for prostitutes for foreign businessmen to drum up investment in his business.