"If there is no alert, the passenger is not stopped unless as part of routine screening procedures."
She said that Customs was working with the Ministry of Health to ensure similar incidents did not occur.
It can also be revealed that the Ministry of Health believes Rathod's "premature departure" from New Zealand was sparked by the death of a family member in India.
Rathod had been "living adaptively" in the community for three years and was considered low risk to the public when he fled the country, the ministry's director of mental health, John Crawshaw, said.
In August last year, the forensic mental-health service applied to the ministry for Rathod's "special patient" status to be removed. The status, which prohibits overseas travel among other conditions, was imposed after a jury cleared him of murdering his wife on the grounds of insanity. The ministry was considering the application to have Rathod's special-patient status removed at the time he left the country using an Indian passport.
Dr Crawshaw said Rathod had been planning to travel to India once his legal status had been changed.
"In preparation for this move, the forensic psychiatric service had been liaising with a mental-health service in India to ensure the individual would receive continuity of care (eg medication) after the relocation," he said.
"A factor likely to have influenced the individual's premature departure was the recent death of a close family member. It is understood that the individual had a strong desire to be with his family following the bereavement."
Dr Crawshaw said Rathod was believed to be the only special patient to flee the country since the current law controlling those found not guilty of crimes due to insanity came into effect in 1992.
Hawke's Bay Today understands it is unlikely a request to extradite Rathod by New Zealand authorities will be made.
The Extradition Act allows New Zealand to request the extradition of a person from any country. Whether another country is able to extradite to New Zealand in the absence of a treaty is dependent on its domestic law.
New Zealand may also be bound as a successor state to extradition treaties concluded on its behalf by the United Kingdom prior to independence, including one with India.
However, the Ministry of Health said it had informed the relevant Indian authorities and mental-health services immediately following Rathod's arrival, of his approximate location and psychiatric needs.
During his 2005 High Court trial in Napier, a jury heard how Rathod killed his wife while suffering a paranoid delusion that she was having an extramarital affair.
An earlier armed robbery of the dairy was suggested as a possible catalyst for his depression. Police said they found no evidence his wife, a veterinarian, had an affair.
A trial in 2004 was abandoned when Rathod collapsed in the dock and he was assessed as medically unfit to continue his defence, while a second trial ended with a hung jury. He was found not guilty on grounds of insanity in 2005 and kept in Porirua's Tane Mahuta forensic mental-health unit.
His departure came a month before killer Phillip Smith fled to Brazil and was recaptured.
