How Do I Remove Time Machine Deleted Back Ups From The 'Trash' On My iMac
OS X 10.13.4 on a late 2009 27" iMac. I have, via Time Machine, not Finder, deleted the 16 oldest backups from an external HDD. When the external HDD is ejected from my iMac, the files disappear from my iMac's 'Trash'. When the external HDD is turned on and connected to my iMac, the files appear in my iMac's 'Trash'. When I empty my 'Trash' with the external HDD connected and the backups showing in the 'Trash', a dialogue box opens telling me 'The operation can't be completed because the item "folders" is in use.' These files do not show up on the external HDD itself. Does any one know how to 'empty' this "Trash'?
iMac, macOS High Sierra (10.13.4), A1312 27" 2.93 GHz i7 Core 8GB 1TB