South Korean newspaper Chosun Ilbo has reported that North Korean leader Kim Jong-un’s ex-girlfriend was among a group of North-Koreans executed by firing squad on August 20.

Citing sources from China, the paper said singer Hyon Song-wol and several other performers were executed in public for violating pornography laws.

The group is said to have included members of the Unhasu Orchestra as well as other singers, musicians and dancers with the Wangjaesan Light Music Band.

They were found guilty of filming themselves having sex and then selling the videos.

An unconfirmed Chinese source said: “They were executed with machine guns while the key members of the Unhasu Orchestra, Wangjaesan Light Band and Moranbong Band as well as the families of the victims looked on.”

The source also reported that the families of the executed people seemed to have been sent away to prison camps, following the country’s “guilty by association” law.

Kim Jong-un is reported to have met Hyon ten years ago but Kim Jong-un’s father forbade the relationship and both went on to marry other people. However, according to Chosun Ilbo there have been rumours that the two were having an affair.

The newspaper said that Kim Jong-un’s wife had also sang with the Unhasu Orchestra before her marriage to the leader, adding: “Whether she had any hand in the executions is unclear.”

Speaking to UK newspaper the Telegraph Toshimitsu Shigemura, a professor and expert on North Korean affairs said: “If these people had only made pornographic videos, then it is simply not believable that their punishment was execution…They could have been made to disappear into the prison system there instead…There is a political reason behind this.”

Hyon was known for singing with the Pochonbo Electronic Ensemble which performs propaganda and revolutionary songs. Her popularity reportedly peaked in 2005 with her song “Excellent Horse-Like Lady”.

Reportedly the Unhasu Orchestra and the Wangjaesan Light Band have both been disbanded due to the pornography scandal.