I watched this movie a while ago on sbs, it is european, about a male detective. Maybe released 2000-2010.
At the beginning he pretends to be a cop to arrests this boy, he steals hash from him, the hash the called "Black Afghan". He goes back somewhere to smoke it with this other guy.
He goes to this other city for most of the movie, I think in the end the crime doesn't get resolved he just leaves the city maybe??
There are these big group showers at some point, I think it is like a homeless shelter situation. At some point the protagonist and a girl get locked in the shower and someone turns it on very hot, they are like struggling in the shower for a good while, putting up their coats against the shower head to shelter themselves from the water.
So I think there is some kind of sex trafficking. There is a (opera?) singer client that wants a girl to pee into his mouth. There is something mentioned about them getting checks for std's and stuff.
There might be government involved?