A Chinese dealer in antiques was sentenced to 70 months in prison on Tuesday as the ringleader of a crew that smuggled rhinoceros horn and elephant ivory artifacts from the United States to China.

The sentence imposed on Li Zhifei, 30, in US District Court for smuggling more than $4.5 million in goods is one of the longest ever in the United States for wildlife smuggling.

Li, the owner of a firm called Overseas Treasure Finding in Shandong province, admitted that he led three other antiques dealers in the United States who helped him smuggle the items.

Li was arrested in January 2013 after buying two horns of the endangered black rhinoceros from an undercover US Fish and Wildlife Service agent in a Miami Beach, Florida, hotel for $59,000.

The sting was part of a US Justice Department crackdown on wildlife smuggling.

Li's crew smuggled 30 rhinoceros horns and numerous objects made of rhino horn and elephant ivory to China.

He pleaded guilty to 11 related counts, including seven counts of smuggling. He was transferred to New Jersey in 2013. The 70-month sentence imposed by US District Judge Esther Salas was the minimum under federal guidelines.

Li must serve two years of supervised release and forfeit $3.5 million in proceeds. He agreed to be returned to China, his lawyers said.

Wang Qiang, a New York dealer working with Li, was sentenced in December to 37 months in prison.