A federal judge in the US state of Vermont has ordered the release on bail of Turkish PhD student Rumeysa Ozturk, who was controversially detained by immigration agents in late March.

"The court finds that she does not pose a danger to the community, nor does she present a risk of flight. The court orders the government to release Ms. Ozturk from custody immediately," Judge William K. Sessions III said on Friday.

The judge added that Ozturk is free to return to her home in Massachusetts.

"She's also free to travel to Massachusetts and Vermont as she sees fit, and I am not going to put a travel restriction on her, because, frankly, I don't find that she poses any risk of flight," he said.

The judge said Ozturk’s career requires her to attend out-of-state programs and give out-of-state lectures.

"And as a part of her career, I think she's very lucky to be travelling outside of these areas," he added.

Ozturk, a doctoral student at Tufts University, appeared remotely at the court hearing in Burlington, Vermont, more than six weeks after she was arrested on March 25 by Immigration and Customs Enforcement (ICE) agents in Massachusetts for co-authoring an op-ed last year about the Israeli-Palestinian conflict in the school’s student newspaper.

The hearing came after the Second Circuit Court of Appeals had ordered earlier this week that Ozturk be transferred from an immigration jail in the state of Louisiana to a federal district court in Vermont.

Her lawyers at the American Civil Liberties Union argued that her detention violates her constitutional rights, including free speech and due process.

“Completing my PhD is very important for me”

During the hearing, Ozturk said she has suffered increasing asthma attacks since her detention, listing the triggers as stress, insect and rodent droppings, and lack of fresh air.

"I believe there are different reasons. First of all, the wrong conditions, as I described in my declarations, is really challenging for an asthma patient, because there is constant exposure to those triggers, there is, like most proper air ventilation. We are not allowed to take fresh air when we need to take it," she said.

Ozturk said she is also "constantly exposed" to cleaning supplies.

When asked about her plans if the court does grant her bail, Ozturk said her lease will end in May and she will move to Tufts University's housing "as soon as" she is released.

"Completing my PhD is very important for me. I have worked for this PhD for a long time. I have been in graduate school over the last seven years.

"The work that I do is really meaningful for me, because I believe I am doing my best to learn, grow, connect, to develop as a developmental scientist, as a child development scholar, to contribute to well-being and development of children all around the world," she added.

Ozturk's asthma has worsened 'significantly'

Witness Dr. Jessica McCannon said Ozturk's asthma has worsened "significantly."

"So she's currently living in a space which ... is designed for 14 people sitting, and she is essentially living with 23 other women in the space, exposed to the humidity from the showers ...and exposed to strong odors from detergents, shampoos, cleaning supplies, and ... not to mention the considerable stress that she's experiencing. All of these things are known to worsen asthma," she said.

While McCannon was delivering her remarks, Ozturk had an asthma attack and she got permission to leave to use the bathroom.

"If she remains in detention, I believe that her asthma control will worsen," McCannon said.

Another witness, Sarah Johnson, a professor and director of Graduate Studies in the Department of Study Development at Tufts University, said Ozturk is scheduled to be a research assistant on a project.

"She's our media expert on that project. Her expertise is absolutely critical," Johnson said.

Johnson said while being in detention, Ozturk is at risk of not meeting the December deadline to finalise her dissertation, adding she has already missed out other projects as well.

"An absolutely major one that she missed was ... presenting her work at a major professional conference in our field. She was scheduled to present there last week," she added.