An MP in Tonga, Dr Fred Sevele, says the country has lost nearly 10 million US dollars in unpaid customs duties over the last 12 months.
Dr Sevele has raised the issue in Parliament after he discovered a container load of rum had been released by Customs without duty being paid.
The container should have cost 61-thousand dollars in duty.
Dr Sevele says it was not an isolated case.
He says records show that 90 percent of cigarettes sold in Tonga in 1998 were sold duty-free.
Dr Sevele says he is encouraging the government to lower import duties but he says the law is not the problem.
"At the moment the laws are reasonable but they just have not been enforced in some ways, you know and that's the crux of the problem. It is an area where we've got to be brutal with in order to stem any increase in corruption."
Dr Fred Sevele says he has been given assurances by the government that staff involved in the most recent incident will be dealt with.