There are two great international camps I know of in Europe.
One is in England, held by Alan Richardson, Technical Adviser and Clinic Director of ULEB (governing body for the EuroLeague and other competitions in Europe). Check his website for his impressive resume and everything you need to know about his camp:
www.candobasketball.co.uk
I'll attend his camp in July. If you'd like to know more about it, send me a PM!
The other is in Poland. Beside many other FIBA certified international referees (Kotleba, Richardson, Rigas, to name a few) from all over Europe, Tomy Nunez is in attendance. Looking at the staff, this might be one of the best camps you can attend not only in Europe, but world-wide, especially if you are interested in international basketball. Check their website:
www.eastmeetswest.pl
Cheers,
Kostja