Tennis legend Martina Navratilova is taking aim at sportswear giant Nike for trying to hide its apparent involvement in research programs concerning transgender athletics.

On Tuesday, Nike refused to say whether it was funding transgender research of any sort. Still, a story over the previous weekend published by the New York Times seemed to provide evidence that Nike is financing at least one study of trans athletes being conducted by Joanna Harper, a man who identifies as a woman.

That entry concerning Nike’s involvement in funding trans athlete research sent Navratilova to her social media account to blast the sportswear giant.

On Tuesday, Navratilova was spurred to make her comment after women’s sportswear company executive Jennifer Sey took to her own social media to express her shock at Nike.

“I’m still stunned by this. @Nike is funding a study that disfigured young boys to understand if they can be physically impaired enough to compete with girls without significant ‘retained male advantage’. Why is a sneaker brand doing medical experiments on children?” she wrote.

The tennis legend then re-posted Sey’s comment, adding, “Joanna Harper is going too far…as is Nike, needless to say. Nike- same company that docked Allyson Felix for being pregnant. So she left and formed her own company, SAYSH. So thanks for nothing , Nike.”