North Korean leader Kim Jong Un's former girlfriend was among a dozen well-known North Korean performers who were executed by firing squad on Aug. 20, a South Korean paper has reported.

The Chosun Ilbo daily on Thursday quoted sources in China as saying singer Hyon Song Wol was arrested along with 11 others on Aug. 17 for violating North Korean laws against pornography, and they were executed in public three days later. They were accused of videotaping themselves having sex and selling the videos.

Hyon was a singer with the Pochonbo Electronic Ensemble, famous for revolutionary and propaganda songs. The victims reportedly included Mun Kyong Jin, head of the Unhasu Orchestra. Kim's wife, Ri Sol Ju, was also a member of the Unhasu Orchestra before she married him.