Sure, could be, but Viktor's been already locked up for, what, almost 15 years? I'm guessing if he had any dirt to dish he would have done so already.
Dear Leader was trying to keep his criminal pals from getting to the point where they'd need to make deals with the prosecution.
Maybe we're both right, Viktor already gave up some dirt on Vlad and had no more to give so he had no remaining value. Unless, of course, he's now a full fledged spy for the U.S.
It seems like a completely amoral guy like him might be convinced to spy for a few bucks, though.