The U.S. Fish and Wildlife Service announced Thursday that it would allow a Texas man to import the trophy of an endangered black rhinoceros should he kill one on an African safari trip he won as part of a conservation fundraiser.

The agency said importing the carcass from Namibia would meet the criteria of benefiting conservation under the Endangered Species Act.

Corey Knowlton bid $350,000 last year during an auction at the Dallas Safari Club last year that was billed as a fundraising effort to save the black rhino.

The club’s executive director said in a December letter the money raised from such actions is “critical to supporting the Namibian government in their efforts to stem the tide of commercial killing of these animals.”

Since publishing the initial request in November, the U.S. Fish and Wildlife Service received more than 15,000 comments, as well as petitions with a total of around 152,000 signatures demanding that the request be denied. PETA said Thursday that it will file a lawsuit.

The hunt was postponed and Knowlton's money kept in escrow while the agency deliberated  the permit application.

Dallas Safari Club spokeswoman Jay Ann Cox could not immediately confirm Thursday whether a date has been set for the hunt.

The agency is also allowing Michael Luzich, a Las Vegas investment manager, to import his black rhino trophy. The government of Namibia directly sold Luzich a hunting permit.

Luzich said he had hired full-time security because he had received death threats once his name became public knowledge.

Humane Society of the United States chief executive Wayne Pacelle said the agency is sending a "mixed message," noting rhino poaching is on the rise.

The agency said it rejected permission to import an elephant trophy from Zimbabwe because it would not enhance the survival of the species in the wild.

The Associated Press contributed to this report.