I just read about this on e-budo.com
http://www.e-budo.com/vbulletin/showthread.php?s=aba2d75587ee9effb6893577877f1f35&threadid=25672
just read the posts...very interesting mention on how Japanese police
interrogations were very very serious if you know what I mean.
Posts concern the "pragmatic" relationship between law enforcement and
the yakuza/gangsters...
It goes way back in the movie THE WOLVES set early 20th cent. a bunch
of gangsters try to monopolize a railroad. And even farther back and
without a doubt they wielded serious power during the time of the
Shinsengumi.
Shinsengumi vs Yakuza!