Black Gold was the first Shorthand article published by the Herald and its video was viewed by more than 1.5 million people.
Read the full Black Gold investigation.
The judges commented on how the story's narrative "made powerful imagery the centrepiece of the story".
"Selective editing and real consideration for user experience is critical for successful long-form multimedia stories. Black Gold clearly put a lot of work into this," the judges said.
The Black Gold investigation, which was designed by the Herald's Paul Slater, was also featured on Buzzfeed's 'Top 12 Incredible Photo Stories You Absolutely Can't Miss' listicle, alongside the New York Times, the Washington Post and Reuters.
The project was funded by the Asia New Zealand Foundation.