The illegal trade in wild animal products over the internet is driving the world's most endangered species to extinction, wildlife campaigners claim.
Ifaw says one site offered two-week-old tiger cubs for $1,500
An International Fund for Animal Welfare (Ifaw) probe found 9,000 live animals or products for sale in one week on trading sites like eBay.
Ifaw claims many traders are taking advantage of the internet's anonymity.
The UK Government says it takes wildlife crime seriously, but Ifaw urged it to act urgently.
During a three month investigation, Ifaw found some of the world's most endangered species for sale online - almost all being traded illegally.
These included a live gorilla for sale in London and a Siberian tiger and four baby chimps on US websites.
Animal body parts included hawksbill turtle shells, shahtoosh shawls from the Tibetan antelope and taxidermy specimens of lions, and peregrine falcons - protected by British law.
Ivory items and traditional Asian remedies containing parts of endangered tigers and rhinos were common place.
The report, Caught in the Web: Wildlife Trade on the Internet, said many animals were being targeted by poachers to meet the demands of wealthy consumers.
Ifaw UK director Phyllis Campbell-McRae said unscrupulous traders and sophisticated criminal gangs took advantage of the anonymity afforded by the internet.
"The result is a cyber black market where the future of the world's rarest animals is being traded away.
"This situation must be tackled immediately by governments and website owners."
Of the 9,000 animals and animal parts found for sale by the probe in its first week alone, 70% were from species protected by international law.
Ifaw wants the Department for Environment, Food and Rural Affairs (Defra) to ensure that bans are enforced.
IFAW is warning the public not to purchase any endangered species
Professor William Dutton, director of the Oxford Internet Institute, said: "Laws exist to stop the unlawful use of any communication medium, but governments and agencies need to communicate in order to address activities that span the globe."
Endangered animals are protected under international law by the Convention on International Trade in Endangered Species (CITES), but there are not enough resources to enforce it, the report said.
British native wildlife law prohibits the trade all wild birds and mammals found in the UK.
But researchers found there was a lack of understanding of the legislation. They wants Defra to provide user-friendly information on its own website.
The report urged the department to set up a hotline for easy reporting of suspicious trade.
Defra welcomed the report. Biodiversity minister Jim Knight said: "The National Wildlife Crime Intelligence Unit is working closely with internet service providers to raise awareness of wildlife controls and to enhance intelligence-gathering on wildlife crime.
"Last month, we introduced tough new penalties for people convicted of trading in endangered species, meaning they now face up to five years in prison or an unlimited fine."
He said the penalties give police stronger powers of arrest, entry, search and seizure.
Ifaw says this spider monkey was for sale
The government was also consulting on plans to use powers under EC regulations to cut wildlife crime at home and abroad.
Website owners are being urged to let users report their suspicions and work more closely with government and enforcement agencies.
A spokesman for eBay said its animals policy goes beyond the law in prohibiting the sale of native and endangered species and it was working closely with the Ifaw to ensure the site remained free from illegal items.
"If we are made aware of any listing that breaks this policy, we will end the listing and may, where appropriate, forward it to the relevant law enforcement agency for action.
"We strongly encourage users to report illegal items to customer support."