A Cambodian court has sentenced two Chinese nationals to life in prison after convicting them of production and trafficking of heroin and methamphetamine in one of the country's biggest drug trafficking cases.

The Phnom Penh Municipal Court found the two men guilty Tuesday of smuggling 55 kilograms (121 pounds) of methamphetamine and heroin worth an estimated $3 million from Laos in June last year. The drugs were believed destined for both Cambodia and third countries.

Two Cambodian men involved in the case also received life sentences, one in absentia as police are still seeking him.

A report earlier this year from the United Nations Office on Drugs and Crime described Cambodia as an increasingly important hub for smuggling heroin and methamphetamine as well as chemicals used in their manufacture.