Members of the public and police combined to find a man exposing himself in a popular Christchurch park.
The 19-year-old was caught by a police dog patrol in the Styx Mill Reserve on Sunday afternoon.
It followed more than 10 reported sightings of the man, often doing an indecent act, over three weeks, Christchurch North Community Patrol chairman Sam Hall said.
A police spokeswoman said the man was arrested and given a pre-charge warning.
The warning is an alternative to prosecution for offenders who have committed offences with a maximum penalty of no more than six months imprisonment.