PRIME Minister Hun Sen on Tuesday threatened to close agriculture tycoon Mong Reththy's dry port if outstanding taxes are not paid.

The prime minister also pressed for a broader crackdown on illegal goods passing through the country's southern border checkpoints, which is depriving the government of taxes.

"Don't blame me if I close [the port], leaving employees jobless," he said, during a ceremony in Sihanoukville.

"Today, I ask that authorities help the government to collect taxes from all sea-crossing points, especially Preah Sihanouk province. We have to use this occasion to collect taxes," he said.

He encouraged customs officers, police and the navy to cooperate to curb smuggling and other illegal businesses.

"The authorities have to crack down on traders that don't pay their taxes," he said.

He also warned customs officers and traders to stop colluding to dodge taxes.

Agriculture tycoon Mong Reththy endorsed the premier's pronouncement and urged authorities to scrupulously collect taxes on goods crossing through the southern borders.

"I want all ports to cooperate to collect tax on imported goods ... to take this money to develop our country," he said.

However, he would not provide figures on the volume of goods passing through his facility.

Minister of Economy and Finance Keat Chhon said that tax income has increased this month after falling for the past two months due to declining imports.