Paris (AFP) - French customs officials said Thursday they had intercepted 136 kilos of ivory shipped from the Democratic Republic of Congo en route to Vietnam -- the biggest haul in nearly a decade.

Officials at Paris's main Charles de Gaulle airport found a dozen elephant tusks chopped into 37 pieces hidden in cases under aluminium plates, possibly to confuse scanners.

The haul is the biggest seized by French customs officials since December 2006, when 600 kilos of "white gold" was uncovered.

"This is a sadly typical case," said airport customs official Sebastien Tiran.

"There's one thing that never goes out of fashion and that's ivory," he told AFP.

There were "several criteria" that alerted officials to the possibility of smuggling, he explained. "The route, what is declared, documents linked to the declaration."

"As soon as we have any doubts, we dig," he said.

Ivory ornaments are coveted in Asian countries like Vietnam, Thailand and China, and activists say Africa's wild elephants are being pushed to extinction by the trade.