Commuter Cherie Howie said she had been stuck on the southern line at Middlemore for about 20 minutes.
Travellers had been advised by train staff of an "obstruction on the tracks".
One person took to Twitter to express their disappointment with Auckland Transport because of the delays.
"We waited between the Otahu and Middlemore station for over half an hour. We were then taken back to Otahu and told that the southern line was stopping there. Extremely unprofessional."
Passengers on the southern line were reportedly advised to get off the train and catch a bus.
A person who did not want to be named said there was still "100-odd people waiting on the side of the road" when I got on the bus.
Police received a report of a person walking on the train tracks in Papatoetoe around 7pm.
Police attended, but the person was no longer on the tracks.