NEW DELHI (AFP) - A British bird-watcher was trampled to death by an elephant near a southern Indian tiger reserve he had been visiting for years, his guide and police told AFP on Friday.

The 68-year-old tourist was fatally injured by a charging tusker in the Masinagudi forest of Tamil Nadu state's Nilgiris district on Thursday and was declared dead in hospital, area police chief T. Senthil Kumar told AFP by telephone.

The district police chief identified the victim as Mr Colin Manvell from the town of Havant in southern Britain.

Mr Manvell reached India on Sept 13 and met up with his local guide M. Kumar on Wednesday in Masinagudi village, the guide said.

"He arrived late at night and checked into a private home as all resorts were booked," Mr Kumar said from Masinagudi, which also boasts a state-protected tiger reserve and is popular among wildlife enthusiasts.

"After lunch on Thursday sir, (Manvell) went out on foot for bird watching near a lake which is a watering hole of wild elephants," Mr Kumar recalled.

"When he did not return ... we followed his trail and heard the sounds of a tusker trumpeting loudly," Mr Kumar said.

Masinagudi forest warden Gnanadoss, who uses one name, said the Briton did not notice the adult male elephant creeping up to him until it was too late.

"It swiped him with its trunk and then trampled him on the ground," Gnanadoss said, adding the attack occurred 100 metres from a site where a woman was killed by elephants in 2009.

The profusely bleeding Briton was rushed to a local hospital but there was no doctor to treat him. He was then ferried to a medical facility in Cuddalore city, 23 kilometres away, but he died from his injuries in transit, Mr Kumar said.

He added that the avid bird-watcher had been visiting Masinagudi in February and September every year for the past five years and described him as a "soft-spoken photographer".

"He knew his way well around here, he was aware of the wild elephants and also the dangers that lurk in the local jungles. This is tragic," the guide said.

Indian elephants can grow to 6.4 metres in length and 3.5 metres in height, according to the World Wildlife Fund. They can weigh up to five tonnes.

India is home to some 25,000 elephants but their numbers are dwindling, mainly due to poaching and destruction of their habitats by human encroachment.

Wildlife experts say such attacks have become an increasing problem due to the rampant encroachment of forested areas that are the elephants' natural habitat.