Can't unfollow private team repos that user no longer has access to

I followed a bunch of private repos when a member of a previous organisation/team (the repos belonged to the organisation). Now I am no longer part of the organisation (simplestream) but they still appear in my dashboard -> http://cl.ly/image/2Q0z1A142D1f

I can see no way to remove them from the dashboard. I've put this down as a UI bug although I suspect it probably goes a bit deeper than that.