Tourism is fuelling an illegal trade in elephants that threatens to wipe out the species in Sri Lanka, international conservation experts have claimed.

Campaigners claim that trafficked elephants, some stolen from protected areas such as national parks, are sold for as much as £1.2 million each or rented out for about £6,000 a month.

They feed a demand from tourists for opportunities to pet, play and be photographed with the animals, and it is claimed that they are often sold to sanctuaries and orphanages.

Others are being bough by rich people as status symbols, according to the letter to President Rajapaksa.

Pubudu Weeraratne, chairman of Sri Lanka’s Species Conservation Centre, warned that there were at least 172 illegally captured elephant babies across the country and that the trend now posed a serious threat to the overall population.

The WWF estimates there may be as few as 3,100 elephants in Sri Lanka. Despite wildlife protection laws which require all Sri Lankan elephants to be registered by their owners, Mr Weeraratne said enforcing the law was a problem, not least because the country’s Wildlife Department is legally barred from tracing elephants held on private property.

The threat to the elephants posed by trafficking is compounded by the clearance of large areas of forest to make way for commercial plantations since the end of Sri Lanka’s civil war in 2009. It is believed that around 60 per cent of Sri Lanka’s elephant population now live outside protected areas, leaving them particularly exposed. Joanna Cary-Elwes, of Elephant Family, one of the signatories to last week’s letter, said: “Recent elephant kidnappings in Sri Lanka have unmasked one of the most sinister wildlife rackets. The trade in live elephants is escalating because of tourism.”

She said the theft of wild elephants was masterminded by poaching gangs and assisted by corrupt officials in the country. “After being taken from the forests, calves are being tied up, starved and tortured to tame them for a life in captivity. Many die from stress, or because their bodies simply can’t take the beatings.

“The Asian elephant is an endangered species; numbers have plummeted by up to 90 per cent in the past 100 years. If we do not stop the trade, some of the most significant populations will become extinct.”