David Hausman obstructed justice and created false records when he pretended to help wildlife experts investigate rhino horn trafficking, while in fact taking part in illegal deals.

The 67-year-old faces a maximum of 25 years in prison, although a guilty plea usually leads to some degree of leniency.

At the time of his arrest along with six other people around the country in February this year, Hausman was found to possess four rhinoceros heads and six black rhinoceros horns and $28,000 in cash.

Manhattan US Attorney Preet Bharara said: “David Hausman pretended he was helping law enforcement protect a species from being wiped out but instead he was contributing to the very problem.”

“Trafficking in endangered species like the Black Rhinoceros is an egregious violation of the laws enacted by Congress to protect endangered species from extinction,” a top environmental offical at the Department of Justice, Ignacia Moreno, said in a statement.

“Operation Crash” also saw the arrest of a Chinese citizen, Jin Zhao Feng, who was nabbed in Los Angeles and accused of shipping dozens or more rhino horns to China. The horns are used in traditional Asian medicine, regardless of fears that poaching is driving the huge African animal to extinction.