Multiple people said they saw a naked man cycling in the neighbourhood over the past few days.
The stretch of beachside road where the incident took place connects downtown Auckland to suburbs including Ōrākei, Mission Bay, Kohimarama and St Heliers.
The 9.6km road is a popular destination for runners, walkers and cyclists.
This comes after another nude incident in the area in 2022.
Along the road at a nearby beach, Ladies Bay, there was an alleged incident where 10 people were seen having sex on a grass bank.
A witness at the beach for an after-work swim with his fiancee said what he saw made him feel “revolting”, and that children had been at the beach “just minutes” before.
Ladies Bay in St Heliers has long been known as a nudist-friendly beach.
Sign up to The Daily H, a free newsletter curated by our editors and delivered straight to your inbox every weekday.