The Australian Federal Police say the co-operation from Tongan and Cook Islands police was crucial to a huge cocaine find on a reef off a remote uninhabited island in Tonga's Vava'u group.
The wreck of the yacht, which also contained a man's badly decomposed body, was carrying 200 kilogrammes of cocaine, worth an estimated 120 million US dollars.
The AFP's Assistant Commissioner for Serious and Organised Crime, David Sharpe, says through the trans national crime units spread across the Pacific they have located four vessels carrying cocaine and bound for Australia over the past 2 years.
Assistant Commissioner Sharpe says from those 4 they have now seized just over one ton of cocaine.
"I can say that the significant point about this one is that while the cocaine was destined for the Australian market it certainly didn't stop the fact of Tonga and the Cook Islands providing an extensive capability, investigative capability to assist us, and our message is that our global reach in law enforcement is far and wide."