Earlier in the day a train was delayed for about 15 minutes after taggers wearing black masks vandalised trains at Puhinui Station near Papatoetoe.
Taggers with black masks sprayed paint on two of the three carriages on the train bound for Britomart.
They were wearing hoodies and some wore GoPro cameras on their heads to film the tagging.
"This type of behaviour is incredibly frustrating, not only for police and Auckland Council but also for members of our community whose rates ultimately have to pay for the graffiti to be cleaned up," the spokesperson said.
Police urged members of the public to contact police or Crimestoppers anonymously on 0800 555 111 if they witnessed people tagging.
Taggers delay Auckland train for 15-minute illegal paint job