Celebrity chef Jamie Oliver might be claiming some of his recipes are gluten-free -- but they're actually full of crap 'cause the label's not official ... according to a new lawsuit.
A non-profit called Gluten Intolerance Group of North America is suing Oliver for stamping some of his online recipes with a 'GF' symbol -- which they believe is a straight rip-off of their own label that they're saying is THE official gluten-free stamp of approval.
In the docs, obtained by TMZ, GIG says Oliver is purposely marking his recipes with this logo to make it seem like they've been certified gluten-free, which they argue is crowding their turf. They say he's misleading consumers, and could ruin their rep.
GIG's asking a judge to make Oliver yank his 'GF' online labels, as well as damages. We've reached out to the chef ... so far, no word back.