An Australian man has been arrested at Bali airport after customs officers found two grams of marijuana in his luggage.

Robert Paul McJannett, 48, was arrested after arriving in Bali with his adult son on a Virgin Blue flight from Perth last night.

Bali police allege McJannett was carrying the marijuana in a plastic bag in socks in his luggage.

The head of the Bali Police drugs squad, Colonel Kokot Indarto, said police intended to charge McJannett with article 112 of the narcotics law for carrying drugs from abroad, which carries a penalty of more than five years' jail.

"Because he carried more than two grams, this could not be indicated as users because users limitation is only 0.15 gram. That's why he's aimed with carrying drugs," Indarto said.

Airport customs official Bagus Endro Wibowo said McJannett had initially been uncooperative following his arrest.

"He even ran with the marijuana and tried to flush it in toilet, but the officers managed to avoid it," Wibowo said.

AAP