One of the world’s most revered investigators into the illegal ivory trade has been found stabbed to death at his home in Kenya. American Esmond Bradley Martin was found by his wife, Chryssee Martin, also an ivory investigator, with a stab wound to the neck on Sunday afternoon in Langata, a suburb of Nairobi. He was 75. Kenyan police believe Mr Bradley Martin was killed in a botched robbery attempt. "We have already questioned a gardener and a cook who are employed at the home," Nairobi DCI boss Ireri Kamwende told Kenyan paper the Star, adding that the force had yet to identify the attackers. _______________ Read more: _______________ Mr Bradley Martin moved to Kenya in the 1970s at a time when elephants were being killed in their masses for ivory. This was followed in the 1980s by the slaughter of rhinos for their horns. His research was instrumental in China’s decision to ban on rhino horn sales in 1993 and later a ban on legal ivory sales, effective from the beginning of this year. He said in 2017 that the end of the legal ivory trade in China meant elephants had “distinctly improved” chances of survival. “We must give credit to China for doing the right thing by closing the ivory trade," he told the Star. Mr Bradley Martin had risked his life to document illegal ivory trade and had travelled to China, Vietnam and Laos posing as a buyer to understand black market values of ivory. His most recent research had been focused on how the illegal ivory trade had moved to the countries around China after the ban. The geographer had just returned home to Kenya from a research trip to Myanmar and had been writing up his findings when he died. Mr Bradley Martin discussed his work in an interview with Nomad magazine last year. He said: "In Kenya, there were around 20,000 rhinos in 1970, but by the 1990s, most of the rhinos had been eliminated. The puzzle was: why were all these rhinos being killed, and where was the horn going?" His death has caused shock in the conservation community in Africa. On Monday morning Dr Paula Kahumbu, CEO of Kenyan elephant protection organisation WildlifeDirect, tweeted: “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 at his home in Karen, Nairobi. Esmond led investigations into ivory & rhino horn trafficking. “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. “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 champion.” The UN’s environment programme tweeted: “The fight to save our wildlife has lost one of its most committed soldiers. Esmond Bradley-Martin had served as the @UN Special Envoy on rhino conservation.” Mr Bradley Martin is the second illegal ivory sales investigator to die in east Africa in less than a year. In August 2017, Wayne Lotter, a prominent South African conservationist who had helped expose and jail poachers and traffickers for years, was murdered in Tanzania. The 51-year-old, who had received numerous death threats for his work, was shot dead while travelling in a taxi from Dar Es Salaam airport to a hotel.