Rubbish, a mattress and some pallets were lit on fire under the Hairini Bridge this morning.
A police media spokeswoman said the fire was producing "a lot of black smoke and flames".
She said the police were not required to attend.
A Fire and Emergency New Zealand spokesman said the fire service arrived at the scene at 11.27am.
He said it appeared someone had been living under the bridge, with a mattress, rubbish and some pallets lit on fire.
