Police in the Czech Republic say they cooperated with counterparts in Australia and the US to break up an international drug trafficking gang that allegedly smuggled hundreds of kilograms of cocaine and heroin across four continents.

Czech officials say the group hired smugglers to travel from Prague to Australia with several kilograms of cocaine and heroin each time, amounting to hundreds of kilograms of drugs.

Czech police — who have arrested 60 people on drug trafficking charges — said the international gang smuggled cocaine and heroin worth $US90 million ($130 million) to Australia and New Zealand.

Police said the gang hired couriers to travel in pairs from Prague to Australia, mostly through Los Angeles or Thailand. They always had four pieces of luggage, each containing five kilograms of drugs.

The drugs could not be detected by X-rays or sniffer dogs, police said, without giving details.

In Australia, four couriers have been arrested and received jail sentences ranging from seven to nine years.

The Australian Federal Police, the US Drug Enforcement Administration and the US Department of Homeland Security have been cooperating on the investigation, which is continuing.

ABC/wires