Nope, the collar wasn't still fastened - it was entirely undone. There is no actual "spike" for the buckle it's just a plastic piece.
I've seen the quick release Christmas collars too - but at £4.99 each and knowing full well at least two of my four will "misplace" theirs it's a bit pricey. Just to clarify, if I do decide a collar is too dangerous I wouldn't put it on any of my mob even if I wanted them to be in the Christmas spirit!
Thanks for answering.
Will continue to try and find a picture after I've cooked tea (we're all getting chicken tonight!) - it's probably easier than trying to describe them.
Oh, and they are definately cat collars.