An impromptu singing performance on a radio program left a Korean actor mystified as an unidentified woman's voice seemingly sang along with him.
During his conversation with the host of the program, Park Gun Hyung told the story of serenading his wife when he asked her to marry him.
At the host's urging, Hyung sang the song and noticed that, as he started singing, a woman's voice could also be heard.
Despite looking around the studio, he could not seem to find who had joined him on the song and, after finishing, asked who the woman was the woman singing.
To his surprise, the host said he had heard her as well but had no idea how it happened.
The response sent a chill through the room as Hyung was astonished and actress Hong Eun Hee, who appeared with him on the program, was equally amazed.
While it's entirely possible that the entire incident was the result of some kind of radio hijinks, Hyung's stature as a superstar in South Korea makes it unlikely the hosts would want to trick him.
And the spontaneous nature in which the song came up in conversation leaves a considerably small window of time for someone to pull off a prank.
Check out the video to see if you can hear the 'ghost voice' singing along with Hyung and let us know what you think at our Facebook page.