Twelve North Korean pop stars were executed last week under orders from Kim Jong Un, including a woman rumored to be his former girlfriend, singer Hyon Song Wol. The group was reportedly arrested on August 17 on charges of violating pornography laws by supposedly filming themselves performing sex acts and selling the recordings. Three days later, the group of 12, all performers with Hyon's band The Unhasu Orchestra were killed by machine gun. The victims' immediate families and other members of North Korean pop groups were reportedly forced to watch, then sent to prison camps.

The Moranbong Band in July 2012

“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,” a Chinese source reported. The remaining group members have disbanded. Some were found with bibles, and treated as political dissidents.

Kim Jong Un is believed to have started a relationship with Hyon about 10 years ago, and rumors persisted that the relationship continued during his marriage to Ri Sol Ju, who had also been a member of Unhasu Orchestra. One theory for the sudden roundup is that Ri objected to Hyon's continued high profile in the media.

Watchers of North Korea believe the pornography charges to be unfounded. "If these people had only made pornographic videos, then it is simply not believable that their punishment was execution," Toshimitsu Shigemura, a professor at Tokyo's Waseda University and an authority on North Korean affairs, told The Daily Telegraph.

"Or, as Kim's wife once belonged to the same group, it is possible that these executions are more about Kim's wife," Professor Shigemura added.

UPDATE: You can watch Hyon Song Wol perform her best-known hit A Girl in the Saddle of a Steed below: