Feb. 5 (UPI) -- Police found one of the United States' leading conservationists and ivory trade investigators was found dead Monday in his home in Nairobi, Kenya.
Police found the body of Esmond Bradley Martin, 75, in his house with a stab wounds to neck. His wife, Chryssee Martin, found him dead after she returned from a walk.
"We have launched investigations into the murder of the American conservationist who was found dead in his house in Karen," Nairobi police Chief Japheth Koome told Capital FM news.
Nairobi's Directorate of Criminal Investigations boss, Ireri Kamwende, said the attacker hasn't been identified.
"We have already questioned a gardener and a cook who are employed at the home," Kamwende said.
Martin wrote several groundbreaking reports about the ivory trade and was believed to be working on a new expose about trafficking in ivory and rhino horns.
At one point, Martin served as the United Nations special envoy for rhino conservation. The conservationist persuaded China to end its legal rhino horn trade in 1993 and ivory trade last year.
The American often posed as a buyer and secretly photographed illegal sales of ivory and rhino horn in China, Vietnam and Laos. He first began his work in the 1970s, traveling from the United States to Kenya to investigate the increase in the number of elephant deaths.
Last year, Martin and his colleague Lucy Vigne discovered that Laos had the world's fastest growing ivory trade.
More than 7,245 African rhinos have been lost to poaching in one decade, including 1,028 in South Africa alone during 2017, according to Save the Rhino.
Ivory and rhino horn are hugely profitable with a rhino horn worth $27,000 per pound and ivory at $454 a pound.
"Pound for pound, a rhino horn is worth more than heroin or gold or platinum," Crawford Allan, of the World Wildlife Fund, said to The New York Times last month.
The World Wildlife Fund in Kenya said on Twitter they were "saddened" by Martin's death.
"We're saddened by the untimely death of Esmond Bradley Martin, a respected colleague & friend to conservationists worldwide," the WWF said in a tweet. "He was at the forefront of fighting #WildlifeCrime in exposing rhino horn & elephant ivory trade. He remains an inspiration for all of us."
Dr. Paula Kahumbu, the CEO of Wildlife Direct, said Martin would be remembered for exposing ivory sales worldwide -- including in the United States, Congo, Nigeria, China and Hong Kong.
"It is with deep shock and horror that we learn this Monday 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 and rhino horn trafficking," Kahumbu said