Large quantities of methamphetamine destined for Thailand were seized by police on Saturday during a routine traffic stop, one of two large busts over the weekend.

In Preah Vihear, police found an estimated 144,000 meth pills in the car of Kong Rich, 32, at a traffic checkpoint on Saturday night in Tbeng Meanchey district’s Mohaphal village, according to provincial deputy police chief Chhory Borin.

“Honestly, it was a fluke. We station three kinds of police at each checkpoint: explosives police, traffic police and anti-drug police,” Borin said. “We were suspicious because his eyes were red and he was behaving suspiciously. We called him out of the car for a urine test. It came up positive and he confessed that he had been using drugs. Then we checked his car, where we found piles of drugs.”

During further questioning, Rich confessed that this was the third time he had transported drugs from Stung Treng province to the Thai border, for which he claimed a Chinese national paid him 500,000 Thai Baht ($14,149) each time, according to deputy police chief Borin.

“The ringleader gave them to him and he transported them through the provinces until he reached Battambang, where he handed them over to a Thai national,” Borin said, adding that Rich claims to have acted alone. “We don’t have information about the Chinese and Thai ringleaders.”

An anti-drug police officer in Stung Treng said his team was aware of the existence of the Chinese trafficker but did not know his identity as he is based in Laos. He said that the large number of illegal crossings combined with the lackadaisical attitude of border guards makes it hard to stem the flow of drugs from Laos.

“It’s like they’re not willing or lack a conscience,” he said. “It makes things complicated.”

A UN Office on Drugs and Crime report issued earlier this year designated Cambodia a regional drug-trafficking hub, citing porous borders and limited resources for policing.

Meanwhile, local media reported that two Cambodians were arrested by Vietnamese officials the same day transporting a kilogram of unspecified narcotics across the border in Ratanakkiri.

The pair were identified as Chab Samean, allegedly a border police officer, and An Bunthy, a soldier with Border Regiment 102.

Vann Sangvath, Ratanakkiri deputy anti-drug chief, confirmed that two Cambodians had been arrested by Vietnamese authorities but was awaiting confirmation that they were border officials.

Colonel Ouk Sothy of Border Regiment 102 confirmed Bunthy was under his command, adding that he had a history of drug use.