A vehicle drives past the scene marking the spot where conservationist Wayne Lotter, 51, was shot and killed in Dar es Salaam on Aug. 16. (Daniel Hayduk/AFP/Getty Images)

NAIROBI — A leading wildlife conservationist who pioneered new techniques to catch elephant poachers and ivory smugglers was shot and killed in Tanzania on Wednesday.

Wayne Lotter, a 51-year-old South African, was in a taxi in Dar es Salaam when it was stopped by another vehicle. Two men opened the car door and one shot him.

Lotter had for years received threats against his life, according to his organization, the PAMS Foundation, which he founded in 2009. He worked closely with the Tanzanian government during a period in which poaching surged. From 2009 to 2014, the elephant population in Tanzania collapsed from 109,051 to 43,330, according to government data.

Lotter’s killing is being investigated by Tanzanian authorities. It remains unclear whether his death is related to his anti-poaching work. Reuters reported that his laptop was stolen in the attack.

“Through his work with PAMS he helped train thousands of village game scouts in every corner of the country. His groundbreaking work in developing an intelligence-based approach to anti-poaching helped successfully reverse the rampant rates of poaching facing Tanzania,” the organization posted on its Facebook page.

Dar es Salaam, Tanzania We are heartbroken to share the news that PAMS Foundation co-founder, Wayne Lotter was shot...

Posted by PAMS Foundation - Conservation in Tanzania on Thursday, August 17, 2017

Lotter helped fund Tanzania’s National and Transnational Serious Crimes Investigation Unit, which successfully pursued a number of high-profile ivory traffickers. In 2015, the unit arrested Yang Feng Glan, the so-called Queen of Ivory, who is accused of smuggling more than 700 elephant tusks out of Africa.

PAMS, which stands for Protected Area Management System, works with local communities to curb poaching and has also helped support the Tanzanian government to prosecute and extradite alleged smugglers. It has promoted so-called intelligence-led policing to use modern surveillance techniques to pursue wildlife traffickers.

Lotter helped extradite another alleged smuggling kingpin, Gakou Fodie, from Uganda to Tanzania. Lotter has said that Fodie was involved in the shipment of six tons of pangolin scales. The rare mammal is considered the world’s most hunted animal.

But some of Lotter’s most important, and most emotional, work was related to elephants.

“It is hard to describe the exact feeling, but my stomach still knots every time I see an elephant carcass. I have seen hundreds over the last three years,” Lotter wrote in 2014 for ITV News.