Police have re-opened streets in Whangarei after reports of a suspected gas leak on Thursday.
The Fire Service says it had many calls from people in the central business district, reporting a strong smell of gas about 2.30pm.
Police diverted traffic and evacuated several buildings in the Rust Avenue Bank Street area, including the National Bank.
Fire crew with gas detectors did not find any sign of a leak.
Fire Service officer Ron Wilson says the gas is thought to be from methane from the sewers forced upwards by warm and still conditions, full stormwater drains and a spring tide.
Mr Wilson says council staff will monitor the situation over the next few days to see if the gas persists.
Police say there was no danger to the public.