NOTE: This has been upgraded to Spoiler. Please add your comments there.
I've been sent this from PeachfaceIsland. I'll update when I get any more information, however, I would say that this is most likely authentic.
Hurley's brother was seen briefly in Numbers.
UPDATE 11th Nov: The original poster has contacted me and said the following "I had it wrong, they are looking for Hurley’s little “skinny” brother. "I can't believe it, but I actually have Lost scoop. One of my coworkers has two young sons who are in acting. The older of the two, is soon going to be going up for the role of a young Hurley. Her son is 13, Cuban-american, and NOT overweight. She actually doesn't really think he has much chance of getting it (because his resume isn't that long) but is thrilled nonetheless. Trust me, I'll post more info if I learn anything.
Source: Anonymous