/usr/pkg cleanup, files not owned by any package

[Mayuresh <mayuresh%acm.org@localhost>]

I do not know how this would have happened, but I find there are files on
my system under /usr/pkg, on which if I run pkg_info -F -e <filename> it
says they are not owned by any package.

I'd just like to remove those files that are not owned by any package to
clean up /usr/pkg (at least bin and lib directories as at least in theory
etc can have files that are hand made).

Is there any tool that can help do such clean up of /usr/pkg area?

Mayuresh