Illustrator: Selection Tool is selecting an extra asset that doesn't exist

The file is constantly selecting an empty space / dot I don't know what, could someone tell me how to. trouble shoot this?

The selection also rotates, flips etc. with that additional 'thing'

I have restarted my system, resaved the file, checked for all hidden layers and it's all empty.

Please let me know what this is and how can I get rid of it? 

Thank you