rsync --delete not working (no wildcards)

[Stewart Jeacocke]

Hi,

I'm trying to copy some directories with rsync and would like to
delete files from the destination if they no longer exist in the
source.

I'm using the following command:

rsync -v --archive --hard-links --delete --force
--filter=':/.rsync-filter' /opt/ /mnt/backup/opt/

/opt does not contain any files
the destination contains one file

stewart at attobeast:/etc$ ls /mnt/backup/opt/
test-file

after running the rsync command I would expect test-file to have been
deleted but it isn't. I'm sure I'm missing something obvious in the
man page that explains this behaviour but I can't figure it out. Can
anyone enlighten me?

Thanks

Stewart