An illegal shipment of 200 kg (440 lb) of ivory destined for Malaysia has been seized at Zimbabwe’s main airport, an official said on Wednesday.

Security agents from Zimbabwe’s Parks and Wildlife Management Authority intercepted the shipment on Monday, its spokesman Tinashe Farawo said. The ivory was stashed in four boxes at Robert Mugabe International Airport.

Controlled ivory trade is allowed in Zimbabwe, but its export is not permitted. Farawo said at current market prices of $2,100 a kg, the ivory was worth $420,000.

“We have made contact with the travel agent involved to identify the owner of the ivory. We are also investigating its origin,” said Farawo. He did not give further details.

Farawo said although state security agents had in the past arrested people trying to smuggle ivory through airports, this was one of the largest interceptions they had made.

Zimbabwe, together with Namibia failed last year in October to convince a U.N. body that they should be allowed to export elephant ivory, moves the countries argued would protect the animals rather than endanger them.

Ivory is prized for its decorative qualities while rhino horn is a key ingredient in traditional Asian medicines. There is also speculative demand from buyers betting that prices will skyrocket if rhinos are poached to extinction.