The Global Organisation of Parliamentarians Against Corruption, or GOPAC, is calling for a more inclusive approach to tackling corruption in the Pacific.
Tonga is the latest country to sign onto GOPAC after the Cook Islands and Kiribati.
The organisation's chairperson, John Hyde, says tackling corruption in the region cannot be achieved without including those in power.
"You can have well meaning activists that say we've got to do this, got to do this but if you don't bring the government if you dont bring the elite, the decision makers, the big business people that control the economy. If you don't bring them on board, then you are not going to succeed."
Mr Hyde says corruption is a serious problem in the Pacific with 60 percent of business people saying they expect to have to pay a bribe within the next year so they can carry out their normal business activities.