A consumer watchdog group is questioning the credibility of a widely reported Stanford University study warning that ethanol use could be harmful.

The Foundation for Taxpayer and Consumer Rights says the school’s ties to ExxonMobil make the study’s findings “difficult to accept.”

ExxonMobil has given $100 million to fund Stanford’s Global Climate and Energy Program (GCEP). Though the ethanol study was not directly funded by that program, the author had a three-year grant from GCEP to study the impact of replacing fossil-fuel motor vehicles and electric power plants with hydrogen fuel cell vehicles and power plants.

The public cannot accept the results at face value when ExxonMobil has funded a major energy research program at the university and research results are in line with the giant oil firm’s corporate goals, FTCR said.

ExxonMobil Chairman Rex Tillerson is dismissive of ethanol’s prospects, recently telling Fortune Magazine, “I don’t have a lot of technology to add to moonshine.”

The study based on computer models has received widespread publicity, despite the fact that the model is controversial because it assumes complete conversion to ethanol use rather than partial.