Four Spanish nationals are in police custody and facing charges of trafficking 300 kilos of cocaine worth $78 million.

Ivan Maria Ramos Valea, 35, Julia Maria Boada Fernandez, 37, Miguel Angel Sanchez Barrocal, 38, and Jose Herrero-Calvo, 39, were charged with importing or exporting a commercial quantity of border controlled drugs, considered the fifth-largest cocaine seizure in Australian history, before the Bundaberg Magistrates Court Monday. The four were all arrested on Friday and the hearing of their case starts on Jan. 12, 2012.

Valea and Fernandez were arrested aboard the yacht Friday Freedom, where police found cocaine in sealed plastic bags hidden in the bilge. Barrocal and Calvo were separately arrested after leaving the yacht each carrying a suitcase filled with 100 kilos of cocaine.

Some $3.5 million in cash found in the homes of two of the suspects in Sydney and Gold Coast were also seized by police. Barrocal is suspected as the ringleader after he drove from his home in Sydney to Gold Coast and then to Bundaberg to help move the drugs believed sourced from South America.

Police have been monitoring the yacht since it left Port Vila in Vanuatu on Oct. 14 and arrived at Bundaberg on Oct. 20. The suspects did not make any move until three weeks later on Nov. 11.

The Australian Federal Police (AFP), the Australian Customs and Border Protection Service, the Queensland Police Service and Vanuatu authorities worked together to bust the drug syndicate in an operation named Avalon.

The volume of the seized drug indicates the growing local demand for the illegal drug, according to Customs National Manager Enforcement Operations Kaylene Zakharoff. Last year, the AFP's total drug haul was 796 kilograms, 103 percent more than in 2009.

The Australian Federal Police seal.