https://newtoki469.com/webtoon/54139050/%ED%95%B4%ED%94%BC%ED%88%AC%EA%B2%8C%EB%8D%94-16%ED%99%94?stx=%ED%95%B4%ED%94%BC%ED%88%AC%EA%B2%8C%EB%8D%94&sst=as_update&sod=desc&toon=BL%252FGL&spage=1
You can read it here. Still this is just my assumption. But I just hope he’s not directly and intentionally related to the case. ╥﹏╥
My guess is that the club was maybe co-owned pr solely owned by Seungmin where Jaeyoung was drugged of which eventually ruined his career. Even though Seungmin knew and is in a mission to catch the culprit who distributed the drug in his club, he has just recently found out the extent of the damage the drug can caused to someone. There was also a scenario shown that he might have been unknowingly in communication with the person/organization related to the drug. So, in a way he felt like he had a hand in what happened to Jaeyoung.
I promise you that this is only my interpretation of what I’ve understood of. So it may be way off track from what the story plot is actually about. And for that I apologize in advance. ( ̄∇ ̄")

Seungmin is boyfie-ing so hard and every subtle moves he makes send armies of butterflies to my stomach. (▰˘◡˘▰)
However the coming revelation is gonna frustrate us so much I hope whatever they’re feeling towards each other stands strong. ヾ(❀╹◡╹)ノ~