Well, that is novel! I'm tempted to suggest that the civil servant wrote down a sound of blank bewilderment, mistaking it for a word ... but it's more likely that he's just left out the vowels in good Semitic fashion. But I've never heard the like ... except that when I was growing up in Cape Town there were hundreds of local Moslem guys named Mohammed and it was regularly shortened to Gamat or Gammat (with the G, as they say, like the ch in loch). Perhaps there's a bit missing?
Would it be possible to ask him, and then let us know? I'd be fascinated.