A man who allegedly tried to import almost 80 kilograms of kava from Tonga has been caught at Sydney Airport.

Customs officers seized 77.6 kilograms of the powder after the 48-year-old passenger arrived in Sydney last Thursday.

The kava, a social and ceremonial sedative drink popular among Pacific Islanders, was contained in plastic bags in his hand luggage.

It is illegal to import more than two kilograms of kava without getting permission from the Office of Chemical Safety before travelling, Customs and Border Protection's Allison Denny-Collins says.

"For larger amounts of kava, importers must obtain a licence to import controlled substances and also an import permit for each consignment of kava," she said.

The maximum penalty for smuggling kava is $170,000.

Kava is also used in remote indigenous communities in Australia.

Excessive use can lead to kidney and liver damage, as well as negative physiological and social impacts.