Helms has been out of office since 2003, and I don't think we've had an NEA controversy for a few years.

There was the case of the "NEA Four"--performance artists Karen Finley, Tim Miller, John Fleck, and Holly Hughes--who were awarded funding, but their funding was revoked in 1990. In court they were awarded compensation greater than their original grants in 1993. Not photography, but it might be what you're looking for.

Andres Serrano of "Piss Christ" fame received an NEA grant that was revoked, and also received an earlier grant from an organization that was partially funded by the NEA.

Chris Ofili, whom Jorge mentions for his portrait of the Virgin with elephant dung, is a British artist of African descent, so he wouldn't be an NEA candidate. The Brooklyn Museum may have received NEA funding, but as I recall, the controversy was over New York City funding for the museum, not the NEA, since it was driven by Rudolph Giuliani.