﻿A deportee was able to fly back to New Zealand after a Jetstar employee purposely spelt their name incorrectly to avoid an Immigration "do not board" warning.

Jetstar was fined $12,000 at the Manukau District Court on Monday for letting the Chilean passenger board a plane from Bangkok to New Zealand, breaching the Immigration Act.

The airline pleaded guilty to the charge, which carries a maximum fine of $50,000, at an earlier hearing.

A Jetstar check-in agent ignored the Immigration New Zealand warning flag which advises airlines if a passenger attempting to board should not be allowed into New Zealand.

The agent entered the Chilean passenger's name three times, each time triggering a "do not board" warning.

The agent then deliberately misspelt the passenger's name - allowing a ticket to be issued.

Immigration New Zealand national border manager Senta Jehle, said she was seriously concerned with the incident and had no alternative but to prosecute the airline - the second time Jetstar has been prosecuted for this type of offence.

"This case is particularly serious as the passenger was the subject of a deportation order in 2014 which excluded him from returning to New Zealand for a period of five years.

"An alert was in place to prevent him from travelling to New Zealand and the airline totally ignored the alert and the instruction from INZ," she said.

Jetstar has already had 14 infringement notices in relation to failing to comply with the "do not board directive" between July 2012 and February 2016.

During that period, they were also issued with another 325 infringement notices for breaching other aspects of the immigration act.

"INZ takes this type of offending very seriously as airlines have a crucial role to play in maintaining the integrity of New Zealand's immigration system and keeping the border secure," Jehle said.

The passenger was sent home from New Zealand the following day.