Everlee Wihongi has been free from ICE detention

New Zealander Everlee Wihongi's sister-in-law has described the huge sense of relief after confirmation the Kiwi has been released from immigration detention in the United States.

Everlee, 37, was detained by ICE while attempting to return to the US on a Green Card - or Permanent Resident Card - after a three-week holiday in New Zealand in early April, because of a 2016 cannabis conviction.

Her lawyer Marc Christopher confirmed on Saturday morning (NZT) that she has been released and is expected to be reunited with her family in the next few hours.

Everlee's sister-in-law Courtney Wihongi told Saturday Morning their joy was enormous.

"I can't even put into words how we are feeling right now," Courtney said.

After initially being unable to find out whether today's scheduled hearing had gone ahead, and being unable to make contact with Everlee, they got the news and were able to speak with her over FaceTime.

"That's when it really hit that she's actually out and that she's actually free.

"It's been a rollercoaster the past 24 hours."

Everlee was originally detained in California two months ago, but was later transferred to Arizona, and has now been released in Arizona. The family were planning to get her back home to Wisconsin in the next few days.

Courtney said her sister-in-law would need to do some healing after the experience and the conditions, including being housed in rooms with up to 60 other people at a time.

"At the moment she's so content to be out and to be free."

But: "It's no conditions that any human being should have to endure ... it's been terrible," Courtney said.

The family would also be breathing a sigh of relief that the fight was over, as work to monitor her situation and help progress Everlee through the US court system had taken a lot of energy.

"Every day I was contacting journalists, researching things, trying to reach out to different people that could possibly help, working with the legal team that we had. It was definitely no sleep and working on this 24/7 for the last two months.