Hidden photos in Apple 'Notes'

On my laptop I found about 50 photos that aren't mine - maybe somehow downloaded on an attachment on my iPhone? I don't know, but I want to remove them all.

Anyways, spotlight or search can't locate them, and I can't delete them. (greyed out) I can change the name and move them - then delete, but when I go back to notes they're all still there.

So renaming, moving and deleting does nothing at all? That's a new one on me.

Can anyone tell me how I locate and remove the hidden files? I've tried searching the file number but nothing, they don't come up anywhere. Weird.

This is in apple 'Notes' app, which doesn't come up as a topic tag... Thanks