The German government says it is seeking consular access to one of its nationals, a U.N. sanctions expert who has been held in Tunisia since March. Foreign Ministry spokesman Rainer Breul said Friday that German officials raised the detention of Moncef Kartas with Tunisia"s ambassador last month and sent several diplomatic notes directly to Tunis, most recently on Thursday. Kartas" family says the dual German-Tunisian citizen is being investigated for "allegedly possessing and disclosing intelligence information concerning national security to foreign governments." Breul said the United Nations has the lead on the matter because Kartas, a member of the U.N. panel of experts monitoring sanctions against Libya, has claimed immunity due to his work for the global body.