He then moved on to become the chief executive of the Environmental Risk Management Authority for six years from 2005.
After that, Forlong was the inaugural chief executive of the Environmental Protection Authority established in 2011.
He is due to start as CEO of Predator Free 2050 Limited on July 11 - stepping into the shoes of acting chief executive Brett Butland, who has led the company since Abbie Reynolds left in August.
Predator Free 2050 Limited chairman David Macleod was delighted by Forlong's appointment.
"Rob will bring his strong leadership credentials and a broad experience of working on interconnected environmental issues to contribute to the predator-free movement."
The government-owned charitable company was set up in 2016 to significantly aid the Government's goal of removing possums, stoats and rats from Aotearoa.
Predator Free 2050 Limited is providing co-funding for 19 large landscape predator eradication projects covering more than 820,000ha and invests in breakthrough research and technology developments, with backing from the Government's conservation budget, the Provincial Growth Fund and the Jobs for Nature programme.