I dont see any evidence hes in the west ham u18s
It's unlikely his international clearance ha come through yet - it can take some weeks.
But it's been reported on in the UK media and on Hammers fan forums.
This forum even details who scouted him in NZ (Tommy Taylor's son apparently):
http://www.westhamonline.net/forum_flat.php?8194120%7C%7C1%7C%7C
http://www.westhamfreeforum.com/lewis-tiller-t6465.html
whufcyouth @whufcyouth Nov 26
17 year old New Zealander Lewis Tiller is set to sign for the club after impressing scouts at a training session in New Zealand.
whufcyouth @whufcyouth Nov 26
Tiller should become part of the U18 side.