The UK is the world's largest exporter of legal ivory, fuelling consumer demand for the product and the poaching of elephants for their tusks, environmentalists have warned.
Analysis by the London-based Environmental Investigation Agency (EIA) revealed the UK was also the largest exporter of legal ivory to Hong Kong and China which, the organisation said, were two of the biggest markets for both legal and illegal ivory.
Between 2010 and 2015 more than 36,000 legal ivory items were exported from the UK, according to legal ivory exports recorded on the trade database maintained by the Convention on International Trade in Endangered Species (Cites).
The UK exported more than three-and-a-half times as many ivory items during the period than the next highest exporter, the US.
More than 13,000 items were exported to China and Hong Kong, the EIA analysis of the database found.
The legal international trade in ivory stimulates consumer demand for the product and masks trading in illegal ivory, the organisation warned.
Wildlife charity WWF-UK has previously warned an elephant is being illegally killed every 25 minutes in Africa's poaching crisis, driven by global demand for ivory.
EIA executive director Mary Rice said: "UK ivory exports are stimulating consumer demand globally, especially in Hong Kong and China, two of the world's largest markets for both legal and illegal ivory.
"Even as the government of China works towards closing its domestic ivory market by the end of 2017, the UK continues to inject a large amount of ivory into China.
"The UK government should stop issuing permits for all ivory exports with immediate effect, not least to show solidarity with the Hong Kong and Chinese governments which have both committed to closing their domestic ivory markets.
"As well as fuelling demand for ivory, the UK's legal trade provides opportunities for the laundering of illegal ivory, both within the country and internationally."
Ms Rice said the UK government had pledged to launch a consultation about further restrictions on the country's ivory trade, something the Conservatives had promised in two successive election manifestos.
She said the analysis would "doubtless come as a shock to many who may have been complacent about the role of the UK in the slaughter of Africa's elephants and reinforces the need for action".
"This huge legal trade from the UK, and the illegal trade it masks, is wholly unacceptable for a country which has previously shown strong leadership on elephant conservation," she added.
A spokesman for the Environment Department (Defra) said: "Protecting elephants and ending the illegal ivory trade is a priority for us, which is why we have invested £26 million since 2014 to tackle this insidious industry.
"This funding helps to combat poaching by strengthening law enforcement, reducing the demand for ivory products and promoting sustainable development to protect species threatened by illegal trading.
"However this is not the end of our ambition as we will continue our role as a global leader in the fight against the illegal ivory trade."