I know, Objects can’t be deleted from a Script. But i have an Idea. I don’t know if it’s possible, so i ask You. 
- Making sure, the current selected Object is that what should be deleted.
- Turning the Script Window into a 3D Window or move the MouseCursor into one.
- Initiate two virtual Keystrokes. First Del-Key and than Enter-Key.
- Turning the Window back to Script-Mode or move the MouseCursor back.
Don’t laugh now, but I rememberd that from my Time with my good old C64 (R.I.P.). There we can Initiate virtual Keystrokes by writing some “Poke’s” into the Keyboard Buffer. Maybe there is a Possibility in Blender to do something similar. Maybe i’m dreaming. If so, don’t wake me up! 
Doc