No esxconsole.vmdk on the affected datastore.
I'm also clear on what the 'other' file types could be but no matter how I query the datastore, I cannot see ANY files that could be classed as 'other'. This is consistent if I query the datastore via vSphere or through the command line - we now have 266GB of 'other' files that I cannot actually see on the datastore!
As a matter of interest, is anyone using VMware Data Recovery in their affected environment?