Australian Federal Police officers are searching for three men who were found clinging to an esky, following the discovery of hundreds of kilograms of cocaine in their capsized boat.

In what police have described as one of the largest cocaine busts in the past 20 years in the state, 365kg of cocaine was found onboard the vessel and in a package found on a beach last week.

An international investigation is underway into the seizure.

It came after three men ran into trouble after their boat capsized in "perilous" waters near Eclipse Island, 17km south of Albany in WA's south, on February 1.

The men were believed to be fishing and set off their EPIRB during the emergency.

The Australian Maritime Safety authority (AMSA) praised the men at the time for having life-saving equipment.

But six days later there was a plot twist when a small black plastic-wrapped package washed ashore in the WA tourist town of Denmark.

The AFP said the next day a seven-metre boat was found overturned in another tourist hotspot town, Peaceful Bay, and was brought to shore by a marine rescue group.

When police searched the cabin cruiser, they found another eight similar wrapped packages each containing 40kg of cocaine. 

Police believe the drugs were collected from the ocean and loaded onto the boat. 

How and when that occurred is still being investigated.

A total of 365kg of cocaine was seized.

Drugs found on boat

Police today revealed they were searching for the three men who were rescued from the capsized boat.

They said they needed public assistance to find the men with arrest warrants issued for the trio. 

Police want to speak to Perth men Mate Stipinovich, 49, and Karl Whitburn, 45.

They also want to speak with Aristides Avlontis, 36, who they believe is from the Northern Territory.

Cocaine not 'safe' 

Acting Commander Graeme Marshall from the Australian Federal Police urged the men to contact police.

He believed the cocaine would have been distributed throughout the community causing more than $235 million in drug-related harm, including associated crime and healthcare.

"The interception of this amount of drugs would be a significant blow to a well-resourced syndicate, and prevents millions of dollars of drug profit from flowing back into the group to fund their next criminal venture or lavish lifestyles," he said.

He said there was a perception by some in the community that cocaine was a safe drug.

"Let me be clear — it is not," he said. 

"Just as importantly, the transnational serious organised criminals who prey on Australia are undermining our national security, economy and social security system."

Superintendent Shaun Senior from the Australian Border Force said officers were monitoring a range of vessels operating across the nation.

"We understand that the Australian border is one of our most critical national assets, and along with our law enforcement partners, we will continue to make the border a hostile environment for criminals trying to import illicit drugs," Superintendent Senior said.