Shawn,
Thanks for the response but we had a Nickname assigned to the IQN originally but the "Delete Host" options were always greyed out (even after removing any mappings).
I used the CLI to try and remove the host and all that acheived was to remove the nickname and leave the IQN.
I assume that the entry has been cachd somewhere as the physical host in question now has a different name (which we can see as an initiator but isn't showing as Discovered).
Cheers for now
Russell