Police and fire officers on Thursday morning attended her electorate office in the central suburb of Morningside.

News outlet Stuff reported a man was seen smashing a hole in the office door, throwing something inside before smoke came through the building.

However, police announced later they had arrested a 57-year-old woman "in connection with a wilful damage incident at an address on New North Road".

"The woman is currently assisting police with our enquiries into the matter and we are not currently seeking anyone else," a spokesman said.

Police found the woman at a property in Coatesville, on Auckland's northern fringe.

A large knife, which may be a machete or small sword, was also found on the footpath, according to passersby in local media reports.

The incident took place about 8.20am, before office hours.

Police were conducting a scene examination, confirming something was thrown through the window without saying what it was.

The building was unoccupied at the time, with its office-holder almost 5000 kilometres away on the frozen continent.

Nearby Yoga Studio owner Deb Fong said she smelled smoke in her building.

"Luckily it was before any of the staff got in," she told Stuff.

"I feel really sorry for the staff next door. They're constantly being hassled."

Ms Ardern and her fiance Clarke Gayford reached Scott Base on Wednesday on their second attempt after a flight on Tuesday was turned back due to poor weather at McMurdo Sound.

After visiting the research station, the prime minister is due back in NZ late on Friday.

Australian Associated Press