Bayer AG’s defense of Roundup weed killer may take a hit after an academic journal said Monsanto Co. didn’t fully disclose its involvement in published research finding the herbicide safe.

A correction issued by Critical Reviews in Toxicology, a journal that analyzes health risks of chemicals, may bolster arguments that Monsanto, acquired by Bayer this year, ghost-wrote safety reviews as lawyers try to convince juries that Roundup causes cancer.

Monsanto has defended the independence of the 2016 review, and the journal isn’t changing the papers’ scientific findings. But the journal’s publisher said Wednesday it’s issuing an “Expression of Concern” linked to the articles because the authors “have been unable to provide an adequate explanation to why the required level of transparency was not met on first submission.”

Allegations that Monsanto ghostwrote scientific literature to rebut claims that a key chemical in Roundup causes cancer, and emails supporting them, were featured at the first trial over the herbicide resulting in a $289 million verdict against the company in August.