The Fire Service were called to Central Otago Wastebusters on Boundary Rd just after 8pm on Thursday and arrived to find the building "well ablaze".
A spokesman for the Fire Service said eight trucks from three different brigades attended.
Today, Detective Alan Lee confirmed that a criminal arson investigation was under way.
"The investigators have worked through a large scene and now we have located the point where the fire started, it is clear that it has been deliberately lit."
He said the complex had been destroyed by the fire, and would be of a great loss to the community.
"Wastebusters is a local community funded organisation that helps many locals with employment, and is at the forefront of local waste minimilisation initiatives.
"The person or persons who did this has affected both individuals and our community as a whole."
Mr Lee was now appealing to members of the public for their help in finding those responsible.
"We need help from our local community. This is a small town and someone will know who is responsible. We need them to contact us."
He said police would also appreciate any photographs or videos of the fire, especially in its early stages.
Jon Kingsford, manager for infrastructure services at the Central Otago District Council, said the depot had been providing recycling services to the community since 2000.
"This is a community organisation made up of dedicated staff and loyal, long-serving volunteers all striving to make a difference for our environment and our local community.
"Thursday night's fire has been a devastating blow to the organisation but there is a lot of passion in the Wastebusters' team and a lot of love out there for this iconic institution - we know the community will rally behind them.
"We're a small community, so someone out there must know something about this week's fire."
Anyone with any information could contact their local police station, or call Crimestoppers on 0800 555 111.
