Years ago one fine day my mother started getting sympathy calls because my father was listed as dead in a local obituary. but of us it was just a bit of humor, nothing serious came of it.
Der Fish
I think Belgium doesn't have a consulate here? Last time I was at the Dutch consulate I think I saw a sign that they also provide consular services for Belgium and Luxembourg. If Belgium has a consulate you should be able to get a statement of life there.
I would think that if one went to the embassy with a passport and photo and perhaps a set of fingerprints with a notarized signature that they are yours, that should suffice.
