Nearly 500 canisters of illegal tear gas made in China and hidden inside innocent-looking lighters and lipsticks have been seized by Swiss customs, authorities said Wednesday.

Michel Bachar, spokesman for the customs service, said officers at Geneva airport uncovered the canisters after they grew suspicious of a package from China supposedly containing electronics destined for a Swiss import-export company.

He said the tear gas was hidden inside pink and yellow-topped lighters and coloured metal-cased lipsticks.

"This is the first time in Switzerland that we find tear gas hidden in lighters," Bachar said, holding up one of the see-through plastic casings filled with an orange liquid.

"Behind each of these lighters, there is a potential victim," he said, demonstrating how someone could offer to light a cigarette and spray an unsuspecting victim straight in the face.

"It sends chills down my spine," he said.

He said the gas was being tested at a laboratory to determine the exact substance and how toxic it was.

He said the canisters were to be sold illegally on the Swiss market.

Pepperspray is legal in Switzerland, but other forms of tear gas are not, and people caught carrying just one small canister face a fine of at least 300 Swiss francs ($323, 248 euros).