The U.S. Fish and Wildlife Service said it will review allegations that Donald Trump Jr., may have illegally killed a rare sheep during a recent trip to Mongolia and imported parts of the animal back to the U.S.

Animal conservation activists said President Donald Trump’s eldest son may have violated a federal wildlife anti-trafficking law after ProPublica reported last week that he shot and killed an argali sheep without proper permits during a personal trip in August. The Mongolian government issued a permit for hunting the sheep after the fact, and it’s unclear what happened to the animal after it was killed, according to the report.

[Spotted: Donald Trump Jr. mistakenly heading toward Pelosi’s office in search of McCarthy]

A spokesperson for Trump Jr. on Tuesday provided a statement to CQ Roll Call denying allegations of wrongdoing related to the hunting permit. In the statement, which was also provided to ProPublica, the spokesperson said the hunting trip was purchased in 2015 at a National Rifle Association auction before his father announced his presidential campaign and all permits were secured through a third party hunting group.

“Mr. Trump paid for his trip to Mongolia on his own, flew commercial and timely applied and secured all required permits through a third party outfitter — as is standard in the industry,” the spokesperson said.