A while back, I found that TurboSquid user who apparently worked at Silicon Dreams during the production of LEGO Island 2 and Island Xtreme Stunts had put up some of the game's assets for sale on the site:
And now I've found more. First, take a look at this LEGO Adventures Magazine comic (thanks to apemax for uploading the scans):
Specifically, these pages:
Take note of some of the model's details: The long legs with stubby toes, the strangely shaped ninja hood, and the detailing where the katana attaches to the hood.
Now, take a look at this model on TurboSquid:
It's exactly the same. On top of that, I did a quick Google search for the artist's TurboSquid username, which eventually led me here:
Yeah, that confirms it - this is an official LEGO model used in magazine comics. And it can be yours for $15!