A South Korean court has found two K-pop stars guilty of illicit sexual relations with a woman and sentenced them to up to six years in prison.

On Friday, the Seoul Central District Court said singer-songwriter Jung Joon-young received a six-year prison term and former boy band member Choi Jong-hoon a five-year term.

Both were members of online chat groups that shared secret sex tapes and made jokes about drugging and raping women, the court said.

Jung's conviction also includes illegal distribution of other videos he took secretly while having sex with women. The identities of the victims were suppressed to protect their privacy.

The court also sentenced each man to 80 hours in "sexual violence treatment" education.

"The defendants are well-known celebrities and friends, but the chat they've had showed that they simply considered women as objects of sexual pleasure, and committed crimes that were extremely serious," Judge Kang Seong-soo said as he handed down the verdict.

"Strict punishment is inevitable as the damage inflicted has not properly been recovered and the victims demand harsh penalties."

Jung admitted distributing the video and others he took, though he argued the sex was in all cases consensual.

Choi denied raping the woman and had argued that he did not remember having sex with her and that if he had, it was likely consensual.

Their case was one of several scandals involving sex crimes and other illegal activity that revealed a dark side of an industry at the centre of the global K-pop craze.

Lee Seung-hyun, a former member of K-pop group Big Bang better known by the stage name Seungri, is also on trial over accusations he paid for prostitutes for foreign businessmen to drum up investment in his business.

On Sunday, K-pop musician and actress Goo Hara was found dead at her home in Seoul.

Before her death, she suffered cyberbullying after she engaged in a public dispute with her former boyfriend, who she said threatened to disclose a sex video featuring her.

(Al Jazeera)