Check this news on eKantipur. It says both Birendra and Dipendra had like German gun and there was not dispute on it what-so-ever. You will get more insight into the case.

http://www.ekantipur.com/kolnews.php?&nid=187349

Who do you think could be the possible external powers or country those were unhappy about the German deal? Do you any involvement of those powers in this case? We got to have serious debate on it and find out the truth whoever is after the killing.

Cheers'