Australia's black market for endangered wildlife is thriving, with mainstream websites eBay and Gumtree caught out listing illegal ivory and native reptiles for sale.

The number of native and foreign species being bought, sold and exported has more than doubled since 2008, with bones, skins and animal teeth all regularly traded online.

Ivory has traditionally been trafficked by sophisticated syndicates, but these items are now appearing on Australian online auction sites.

"DNA can easily tell you whether or not a product contains ivory, even if it's being sold as a counterfeit product," Dr Rebecca Johnson, head of the Australian Centre for Wildlife Genomic at the Australian Museum, said.

In February, federal investigators seized $80,000 worth of illegal ivory ornaments and jewellery at two inner-Sydney addresses.

Earlier this month, Parramatta man John Kolettas was convicted of possessing 78 illegal wildlife products - a record haul.

Among the items recovered by New South Wales police were 11 orangutans and more than two dozen monkey skulls, as well as lynx and otter skins.

Illegal trade adding to global decline of species

Authorities say the estimated $22 billion global trade is adding to the decline of species around the world, particularly elephants and rhinos illegally poached in Africa.

About 6 per cent of seizures globally between 1996 and 2008 were traced back to Australia, a new report by the International Fund for Animal Welfare (IFAW) said.

It found 282 endangered species for sale on 14 websites, with a large proportion of them on eBay Australia.

The ABC found what was purported to be an ivory necklace on the Gumtree website on Monday. That listing has now been removed.

Illegal ivory ornaments are now appearing on Australian online auction sites. ( Department of Environment )

"For ordinary people who might think that buying a little ivory trinket or a reptile skin handbag isn't a big deal, we want to get the word out that it is," IFAW Oceania director Isabel McCrea said.

The trade in live birds and reptiles is flourishing on websites such as Petlink and Adoos.

"Reptile smuggling is huge," Dr Rebecca Johnson said.

"[Reptiles are] the most desirable thing in the Australian market."

The Federal Environment Department has also warned those with an interest in exotic animals to be wary.

"The community - particularly collectors, travellers and online shoppers - should be aware of what they are buying, what it is made of, and where it is from," the department said in a statement.

"Without realising it, [buyers] may be contributing to the decline of threatened species, simply by purchasing what initially looks like a bargain."

Representatives from eBay Australia - which also owns Gumtree - are being briefed by members of IFAW.

An eBay spokeswoman says the company has had a zero tolerance policy towards the selling of ivory and other endangered species since 2008.

"We put very strict policies and monitoring procedures in place with the help of IFAW because we feel strongly that even one listing for this kind of an item on eBay is one too many," she said.

"In a global marketplace that has around 500 million listings at any one time, we rely on organisations like IFAW who are the experts in this area."

IFAW needed to inform the company if those selling endangered species online had become more sophisticated in their attempts to "circumvent" eBay's filters and systems, the spokeswoman said.

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