Conservationists have urged Internet giant Google to remove thousands of advertisements promoting products made from endangered whales and elephants.

Campaign group The Environmental Investigation Agency said Tuesday that it had written to Google CEO Larry Page last month appealing for the removal of more than 1,400 ads promoting whale products and 10,000 ads for elephant ivory products on its Japanese shopping site.

"Google has laudable policies that prohibit the promotion of endangered wildlife products including whale, dolphin and elephant ivory, but sadly these are not being enforced and that's devastating for whales and elephants," said EIA president Allan Thornton.

"While elephants are being mass slaughtered across Africa to produce ivory trinkets, it is shocking to discover that Google, with the massive resources it has at its disposal, is failing to enforce its own policies," he added.

Google said in response to the appeal that advertisements for products obtained from endangered or threatened species are not allowed on its sites.

"As soon as we detect ads that violate our advertising policies, we remove them," a Google spokesperson said in an emailed statement.

Most of the elephant ivory ads are for "hanko" Japanese name seals which are a "major demand-driver for elephant ivory", according to the campaign group.

Signature seals in Japan were traditionally made from ivory, although the practice has dramatically declined in recent years, with man-made composites or certain kinds of stone taking its place.

Other products promoted on the Google Japan Shopping site include those made from parts of sperm, Bryde's, minke and other whale species.

The appeal comes as 178 member nations of the Convention on International Trade in Endangered Species (CITES) gather in Bangkok for a conference on tackling illegal trade in threatened animals.

Poaching for illegal ivory claims the lives of up to 30,000 African elephants each year, estimates the wildlife organisation WWF.

Under CITES, Japan has been allowed to import two legal shipments of ivory since 1999, according to international wildlife trade monitoring group Traffic.

The EIA is a London- and Washington-based organisation that investigates and campaigns against environmental crimes including illegal wildlife trade.