When CBI investigates / closes investigation / reopens investigation depending upon which party you belong to (Reference Mayawati and Mulayam's cases), you think any MP will be foolish enough to go and surrender evidence to the police?... :-)
I think you haven't ever been to a police station before...
Anyway, now that the matter has been live telecasted to the nation -- let's see what the police does, or doesn't do... :-)