Interesting. Here in the US there are things one might describe as chocolate eggs with toys inside — but it's just a chocolate shell, inside of which is a large plastic container (much too big for a child to swallow accidentally) containing a small toy.
Sounds exactly the same, actually, just scaled up. Very interesting.
A less SFW fact: In the UK (and presumably elsewhere) those carrying small amounts of hard drugs may place them in an empty container from inside a Kinder egg and, ahem, insert them into themselves to avoid detection.