Creating an animation and an object has come up I can't remove

[burrkim]

Hello,

I'm creating a 3D Viewpoint animation and it's been a nightmare, but I'm almost there but at some point I have selected on this object, which I can't see in the 'Overlays', it's obviously something to do with the viewpoint and maybe sight/shadow but I can't get rid of it and you can see it where ever the animation moves. 

Please help!