WELLINGTON — The Daesh (so-called Islamic State)-inspired extremist who attacked shoppers in a New Zealand supermarket had been fighting deportation for immigration fraud, leaving the nation's leader expressing frustration at the process.

The new details about the attack Friday in Auckland emerged as the condition of some of those injured in his attack improved.

Three critically injured patients remain in intensive care but are in stable condition, Director-General of Health Ashley Bloomfield said Sunday. Police added that the condition of one of the critically injured patients had improved. Bloomfield said a fourth person still hospitalized is in stable condition, while the three others have been released and are recovering at home.

The attacker, Ahamed Samsudeen, 32, arrived in New Zealand 10 years ago on a student visa. A Tamil Muslim, he applied for refugee status on the basis of being persecuted in Sri Lanka, where a civil war ended in 2009 with the defeat of a Tamil rebel group.

According to his mother Ismail Fareeda, who spoke to a Sri Lankan TV channel about her son, her son was brainwashed by his Middle Eastern neighbors.

Samsudeen’s mother accused neighbors she said were from Syria and Iraq of radicalizing her son in an interview with the Hiru TV network from her home in Kattankudy, 330km east of Colombo.

Immigration New Zealand declined his application, but he won his appeal, gaining permanent residency in 2014.

Police first noticed Samsudeen's online support for terrorism in 2016 and by the following year, immigration agents knew he wanted to fly to Syria to join the Daesh insurgency. They began reviewing his immigration status, fearing he could be a threat.

In 2018, Samsudeen was jailed after he was found with Daesh videos and knives, and the following year, his refugee status was canceled after authorities found evidence of fraud.

“My understanding is that in the process of investigation into the terrorist, it was discovered that some of the documents that he had used in order to get his refugee status looked to have been fabricated,” Deputy Prime Minister Grant Robertson said.

But Samsudeen appealed, triggering a lengthy process that automatically allowed him to stay in New Zealand until his appeal was heard. Immigration authorities tried to argue he should remain behind bars, but in July, Samsudeen was set free.

Police trailed him around the clock, fearing he would launch an attack, but unable to do more. Prime Minister Jacinda Ardern has said her government will change the laws this month to enhance penalties for terrorist plots.

Undercover officers just outside the supermarket were able to shoot and kill Samsudeen within a couple of minutes after he charged at them with the knife.

His appeal against deportation was due to be heard later this month — until coronavirus restrictions delayed the hearing to a date that had not yet been set.

“At the time of the terrorist attack, the offender's attempt to overturn the deportation decision was still ongoing,” Ardern said. “This has been a frustrating process." — Euronews