Which uninstalled package provides a file?

$ apt-file find guestmount
guestmount: /usr/bin/guestmount
guestmount: /usr/share/bash-completion/completions/guestmount
guestmount: /usr/share/doc/guestmount/changelog.Debian.gz
guestmount: /usr/share/doc/guestmount/copyright
guestmount: /usr/share/man/ja/man1/guestmount.1.gz
guestmount: /usr/share/man/man1/guestmount.1.gz
guestmount: /usr/share/man/uk/man1/guestmount.1.gz