Cambodian customs on Friday seized more than three tonnes of ivory – the country's largest-ever haul of elephant tusks – hidden in a container of beans.

The haul was made after the container was scanned at the southwestern port of Sihanoukville, said Bun Chiv, deputy head of the port's customs office.

"We confiscated more than three tonnes of elephant tusks that were hidden in a container of beans," he told AFP.

He declined to name where the container had been shipped from or and where the tusks were destined to go. Local media reported that the container was sent from Malaysia.

"We are investigating this case," Bun Chiv said.

In February, Cambodian police arrested two Vietnamese men who were trying to smuggle nearly 80 kilograms of illegal ivory from Africa.

Conservationists have voiced concerns that Cambodia is emerging as a key transit route for African ivory, which often makes its way to wealthy buyers in Vietnam or China.

Poaching of elephants has risen sharply in Africa to meet demand in Asia.