Yahoo Japan, the country's biggest online auction site, is rebuffing calls to end online ivory trading despite Yahoo Inc. CEO Marissa Mayer's misgivings over facilitating a business blamed for the illegal slaughter of African elephants.

Yahoo Japan doesn't accept that ivory sold on its platform — supposedly imported into Japan before a 1989 ban on international shipments — is a factor behind the sharp rise in poaching on the African savannah in recent years.

Dismissing animal rights campaigners' concerns, even though the ivory business contributes only a fraction of its sales, Yahoo Japan also says that as long as no laws are broken people should be able to trade whatever they like on the internet.