A Chinese national is being charged in connection with the record haul. The suspect, identified as Yao Zeye, was arrested on August 7 after coming to the Phnom Penh central post office to pick up the boxes, said the National Anti-Drug Authority (NADA).
Yao Zeye was charged last week with drug trafficking and faces up to life imprisonment if convicted. Police are looking for possible accomplices.
A total 98kg of MDMA pills - better known as ecstasy – was discovered in the shipment. It is the biggest bust of ecstasy in Cambodia.
Cambodia has taken a hard line on drugs in recent years in response to smugglers turning to the country as a transit point, particularly for heroin and methamphetamine.
Heavy sentences are passed down for drug trafficking, with hundreds arrested including senior officials and foreigners.
In last June, a court jailed a Belgian man for life after he was found guilty of smuggling a kilogramme of cocaine into the country.
The same month, authorities in a separate case seized 120kg of crystal methamphetamine smuggled from Laos.-VNA