Before GOP 2016er Ben Carson was slamming fetal tissue research, the neurosurgeon was conducting studies on fetal tissues himself.

According to a blog post by OB/GYN Jen Gunter that was highlighted by Buzzfeed, Carson participated in a 1992 study that relied on “two fetuses aborted in the ninth and 17th week of gestation.”

Gunter, also a well-known science writer, posted a picture of the study bearing Carson’s name on her blog.

After an anti-abortion group began releasing last month “sting” videos claiming to show that Planned Parenthood was profiting from the sale of fetal tissues to researchers, Carson came out against the practice.

“At 17 weeks, you’ve got a nice little nose and little fingers and hands and the heart’s beating It can respond to environmental stimulus,” Carson said on Fox News, as Buzzfeed noted. “How can you believe that that’s just an irrelevant mass of cells? That’s what they want you to believe, when in fact it is a human being.”

A representative from Carson’s presidential campaign declined Buzzfeed’s request for comment.

Late update: Carson spoke to The Washington Post about the revelation of the study, calling it “desperate.” He acknowledged and defended the study, while noting he has not done research on fetal tissue since. He also said fetal tissue research should not be banned, but reiterated that he believed Planned Parenthood should be defunded.

“This has everything to do with how it’s required. If you’re killing babies and taking the tissue, that’s a very different thing than taking a dead specimen and keeping a record of it,” he said.