Japan has allegedly been over-fishing its bluefin tuna quota for the last 20 years. Australian officials say Japan has overfished its quota to the tune of more than $2 billion.

Fisheries Minister Jim Anderton says new monitoring systems are working well, and that is how the issue has come to a head. But he says that it is not just Japan. Despite blowing the whistle on Japan, Mr Anderton says Australia has also been caught catching more bluefin tuna than it is allowed to.

Mr Anderton says now those countries know they have been caught, they must make sure the overfishing stops now. He says he will be pushing hard for the offending countries' quotas to be lowered as punishment. He says he will be making his opinion clear at a regional meeting on the issue in Tokyo at the end of the year