Police were called by someone who saw the man riding on top of the train.
The train came to a planned stop at the intersection of Waverley and Holland Roads, Eureka, Waikato, at 3:30pm.
A police spokesperson confirmed the man was arrested and taken into custody.
He was charged with failing to comply with the lockdown health order, and further charges are being considered.
Sivapakkiam said the behaviour was not only dangerous, but illegal.
"We are fortunate that this person was not seriously hurt," he said.
During level 4, travel is limited to only what is necessary including trips to the supermarket, to receive medical care or to exercise within your neighbourhood.
"This is an incredibly dangerous act no matter what alert level we are in, and has the potential for fatal consequences," a police spokesperson said.
Since being in level 4, police have issued more than 500 infringement notices nationwide for Covid-19 breaches. and received more than 7000 thousand online breach notifications.
In addition to those, Police Commissioner Andrew Coster said police have received a total of 1394 phone calls by members of the public reporting Covid-19 breaches.
The man is due to appear in Morrinsville court tomorrow.