BANGKOK — Thai police have arrested a suspected kingpin of wildlife trafficking who allegedly fueled much of Asia’s illegal trade for over a decade, officials said Saturday.

Boonchai Bach, a 40-year-old Thai of Vietnamese descent, was arrested Friday in the northeastern border province of Nakhon Phanom in connection with the with smuggling of 14 rhino horns worth over $1 million from Africa into Thailand last month, in a case that also implicated a Thai official and a Chinese and a Vietnamese courier, Thai police said.

Boonchai allegedly ran a large trafficking network on the Thai-Laos border that spread into Vietnam. According to the anti-trafficking group Freeland Foundation, he and his family played a key role in a criminal syndicate that has smuggled poached items including ivory, rhino horn, pangolins, tigers, lions and other rare and endangered species.

Police said Boonchai denied the charges against him. Under the wildlife law, he could face up to four years in prison and a 40,000 baht ($1,300) fine, but authorities said they’re also considering money-laundering and customs violation charges that carry up to 10 years in prison.

“One of the largest known wildlife traffickers in a really big syndicate has been arrested,” said Matthew Pritchett, Freeland’s director of communications. “In a nutshell, I can’t think of anything in the past five years that has been this significant.”

Thailand is a transit hub for trafficked wildlife mostly destined for China, and was considered to have the largest unregulated ivory market in the world before it introduced the Elephant Ivory Act of 2014 and 2015 to regulate the domestic ivory market and criminalize the sale of African elephant ivory. Rhinoceros horns, pangolin scales, turtles, and other exotic wildlife are still repeatedly smuggled through Thailand.

In December, Thai airport official Nikorn Wongprajan was arrested at Suvarnabhumi Airport after he was caught together with a Chinese smuggler and a Vietnamese courier with 14 rhino horns and admitted to being hired to send the horns to one of Boonchai’s relatives, Freeland’s statement said, adding the group helped Thai police with information about Boonchai that led to his arrest.

Steve Galster, founder of Freeland, said Boonchai’s arrest breaks open Thailand’s “largest wildlife crime case ever.”

“This network is connected to a group of moneymen who may be living outside the country. We are working to get arrest warrants out on those people as well,” said Gen. Chalermkiat Sriworakhan, deputy police commissioner. Three years ago, Thailand froze $37 million in assets linked to a tiger trafficking ring in the country’s northeast, after investigation helped by Freeland. In 2016, a court order seized Thai bank accounts and other assets, including a house worth $142,000, belonging to Chumlong Lemtongthai, a Thai who was convicted in South Africa on rhino horn trafficking charges.

Chumlung was imprisoned in 2012 after being sent by the Southeast Asian trafficking syndicate called the Xaysavang network — which authorities say includes Boonchai — to take advantage of South Africa’s permit system for professional trophy hunts. He hired prostitutes to pose as hunters, and organized sham expeditions during which 26 rhinos were killed, according to court documents. Customs papers were then doctored for shipping the rhino horns to Laos.

The decision to go after Chumlung’s assets was made only in 2016, after agents received training in asset recovery. The alleged Laotian kingpin of the Xaysavang network, Vixay Keosavang, remains at large with a U.S. bounty of $1 million on his head.

“We have been looking at this syndicate for over a decade now,” said Onkuri Majumdar, a program officer from Freeland. “They have tentacles all over Africa and Southeast Asia. They are responsible for the slaughter of thousands of endangered animals including rhinos and elephants. And let’s not forget rangers in Africa who have died, killed by poachers financed by men like Boonchai.”