A leading American investigator into the illegal ivory and rhino horn trade has been found stabbed to death in his home in the Kenyan capital.

Esmond Bradley Martin was found dead with a stab wound to his neck at his house in Nairobi after a relative went to check on him after he did not respond to phone calls, police said.

Conservationist Paula Kahumbu said Mr Martin led investigations into the illegal trade of elephant ivory and rhino horn that threatens the two species with extinction.

He was at the forefront of exposing ivory traffickers in the US, Congo, Vietnam, Nigeria, Angola, China and recently Burma, Ms Kahumbu said.

1/3 It is with deep shock & horror that we learn this morning of the death of long time conservationist, Esmond Bradley Martin, whom police say died in suspicious circumstances st his home in Karen, Nairobi. Esmond led investigations into ivory & rhino horn trafficking

— Dr. Paula Kahumbu (@paulakahumbu) February 5, 2018

2/3 Esmond was at the forefront of exposing the scale of ivory markets in USA, Congo, Nigeria, Angola, China, Hong Kong, Vietnam, Laos and recently Myanmar. He always collaborated with Save the Elephants and worked with many of us generously sharing his findings & views.

— Dr. Paula Kahumbu (@paulakahumbu) February 5, 2018

3/3 Esmond was a global authority on ivory and rhino horn trafficking. We send our deepest condolences to his wife. RIP Esmond, pachyderms have lost a great champiom

— Dr. Paula Kahumbu (@paulakahumbu) February 5, 2018

British High Commissioner to Kenya Nic Hailey said in a Twitter post: “A passionate and committed man who made a big difference to our planet. May he rest in peace.”

Conservation group Save the Elephants described Mr Martin as “a longtime ally”, a passionate champion of wildlife and a meticulous researcher.

Illicit demand for elephant ivory has led to devastating losses from illegal poaching as the natural habitat available for the animals to roam has also dwindled by more than half. As a result, the number of African elephants has shrunk from about five million a century ago to about 400,000 – a number which continues to decline each year.

Shocked and very sad to hear of the death of Esmond Bradley Martin. A passionate and committed man who made a big difference to our planet. May he rest in peace.

— Nic Hailey (@HCNicHailey) February 5, 2018

Less than 30,000 rhinos are estimated to remain in the wild due to poaching.

The price of rhino horn skyrocketed as demand has grown in Asian countries, mainly China and Vietnam, where consumers wrongly believe that the horn – made of the same substance as fingernails – has powerful healing properties. Syndicates from Vietnam, China, South Korea and Thailand have been identified as being involved in the trafficking.

Press Association