Actually it was a pure guess, based on obvious statement. But now that you asked - I can. Here is the relevant quote about a "dr" who started the accusation:
"Miller, whose employer, the Hoover Institution, is often described as a âoeRepublican-leaningâ or âoeconservativeâ think tank, has interests of his own. A molecular biologist by training, Miller spent 15 years at the FDA before his fellowship at Hoover; throughout both jobs, he has been a consistent and ardent promoter of genetically engineered foods (or GMOs â" the âoeOâ standing for âoeorganismâ).
And in his advocacy, Miller is positively prolific. A quick web search reveals dozens upon dozens of articles and opinion columns touting the benefits of GMOs to consumers, developing economies and agribusiness â" and a seemingly equal number attacking those that warn about the possible risks of what are sometimes called âoeFrankenfoods.â
Miller was a leading voice in opposition to Californiaâ(TM)s Prop. 37, the 2012 ballot initiative seeking clear labeling of products containing GMOs, and, in the 1990s, was an equally prominent voice in a tobacco industry-backed campaign to discredit the science linking cigarette use and cancer."
Link: http://america.aljazeera.com/blogs/scrutineer/2015/4/17/doctors-behind-anti-oz-letter-have-own-conflicts-of-interest.html