One approach would be to use a record search engine to identify those records that could match your own records.
In addition, in my opinion, it would be a good idea to include identifier data records in your own publicated data records, which could make it easier to identify your own data in case of doubt.
Starting points for the search could be:
Found this overview. It gives a very detailed overview:
Edit: One can contact the "statistische Bundesamt" for additional data. It may require additional time and cost.