A Fire and Emergency spokesperson said the rubbish fire began around 7.40pm yesterday outside the building.
Luckily, no people or taonga inside the library were in danger and the library will still be open today, the Department of Internal Affairs said, although the opening hours may be slightly disrupted.
As the fire is now being investigated by police, the department declined to comment further.
A police spokesperson said they are interested in hearing from anyone who saw suspicious behaviour near the Library between 7 and 8pm on Monday night.
