Unknown user in statoverride file

Unknown user in statoverride file

I had an application installed on my htpc running ubuntu server called
mediatomb, a few months ago I uninstalled it and replaced it with a Plex
install. At the weekend when querying existing users on the machine I
noticed that the mediatomb user and group still existed so I used the
command
sudo deluser mediatomb
to remove the user. A day or so later I went to install htop sudo apt-get
install htop but I found that I was getting an error:
syntax error: unknown user 'mediatomb' in statoverride file.
I thought I would just be able to open the statoverride file using nano
and edit out any references to mediatomb but I wasn't able to open the
file correctly using nano. I ran a grep command
grep 'mediatomb' /var/lib/dpkg/statoverride
which returned two locations in the file which don't exist on the system
anymore. The only way I am able to get around the issue for now is to
re-create the user mediatomb and then everything works fine. Obviously
this isn't a good long-term solution.
What I would like to know is, what is the statoverride file and why does
it retain users in it which have been removed from the system? Am I
removing the users in the wrong or deprecated way?