(CNN) More than 40 doctors, nurses, teachers and other humanitarian workers have signed an open letter to the Australian government, challenging a new bill that could put whistleblowers in jail for disclosing the conditions of Australian detention centers.

The Australian Border Force Bill, which came into effect Wednesday, allows for a jail sentence of up to two years for those that speak publicly about detention centers without the permission of the government.

John Paul Sanggaran, a doctor who used to work at an immigration center on Christmas Island -- an Australian territory in the Indian Ocean -- is circulating an open letter addressed to Prime Minister Tony Abbott, "challenging the department to prosecute" him and others for exposing the "deplorable state of human rights" for asylum seekers in the centers.

"We have advocated, and will continue to advocate, for the health of those for whom we have a duty of care, despite the threats of imprisonment, because standing by and watching sub-standard and harmful care, child abuse and gross violations of human rights is not ethically justifiable," the letter read.

A sign hanging in one of the compounds urges the United Nations to step in. Hundreds of men have been detained at the Australian processing center on Manus Island in Papua New Guinea for 18 months while they wait for their asylum claims to be processed.

Asylum seeker hunger strike – A sign hanging in one of the compounds urges the United Nations to step in. Hundreds of men have been detained at the Australian processing center on Manus Island in Papua New Guinea for 18 months while they wait for their asylum claims to be processed.

An image sent from a transferee to CNN, taken on Tuesday, February 20, showing a hunger striker who he said had collapsed on the ground.

Manus Island hunger strikers – An image sent from a transferee to CNN, taken on Tuesday, February 20, showing a hunger striker who he said had collapsed on the ground.

A hunger striker is carried away on a stretcher from one of the compounds at Manus Island detention center in a photo taken on January 19.

Manus Island hunger strikers – A hunger striker is carried away on a stretcher from one of the compounds at Manus Island detention center in a photo taken on January 19.

Asylum seekers at the Manus Island detention center lie in the heat after several days of hunger striking. Advocates say as many as 700 are refusing food in protest against plans to send some confirmed refugees to another, less secure facility on the island. This image was said to have been taken on Monday, January 19.

Manus Island hunger strikers – Asylum seekers at the Manus Island detention center lie in the heat after several days of hunger striking. Advocates say as many as 700 are refusing food in protest against plans to send some confirmed refugees to another, less secure facility on the island. This image was said to have been taken on Monday, January 19.

"If we witness child abuse in Australia we are legally obliged to report it to child protection authorities. If we witness child abuse in detention centers, we can go to prison for attempting to advocate for them effectively."

A line in the sand

Sanggaran told CNN that the human rights abuses that take place in detention centers have been documented for around a decade.

"There's a long litany of what is going on in Australian immigration detention," he said by phone.

"I'm hoping that it draws a line in the sand that we will not be silenced for whom we have a duty of care. To continue to speak to those currently within immigration detention and concerned about the things they see, to encourage them to come up, (and provide information) which should be available to the Australian public."

A number of organizations, including the Australian Medical Association, Royal Australasian College of Physicians, Australian College of Nursing, Australian Lawyers Alliance, along with several teachers' unions, have also expressed their opposition.

"The new act essentially puts doctors in a dilemma when treating detainees and asylum seekers if they have concerns about the provision of their healthcare," Australian Medical Association president Brian Owler said.

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He told CNN that the bill extends to anyone contracted to work in a detention center such as workers providing security or food services.

"There is no clear reasoning why that's necessary," he added.

Asian migrant crisis

The new bill comes on the heels of a Southeast Asian migrant crisis that saw thousands of refugees -- mainly Rohingya Muslims from Myanmar and Bangladeshis -- stranded at sea.

The Abbott administration has enacted strict laws for asylum seekers to stem the influx of refugees. Since 2013, those who enter Australia by sea can no longer stay in the country while their refugee claims are being processed. They are instead transported to controversial offshore detention facilities on Manus Island in Papua New Guinea or Nauru.

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"What we do is we stop the boats by hook or by crook because that's what we've got to do and that's what we've successfully done," Prime Minister Abbott said in an interview with Australian media last month.

'Chilling effect'

A statement from Peter Dutton , Australia's Minister for Immigration and Border Protection denied the bill would suppress reports of human rights abuses.

"It will seek to investigate leaks of operationally sensitive information, however the public can be assured that it will not prevent people from speaking out about conditions in immigration detention facilities," the statement read.

It also noted that there were "world leading whistleblower protections" in Australia.

But Australian Lawyer Association spokesman Greg Barns disagreed.

"They are very narrow defenses available," Barnes said. "A person can reveal information without getting authorization if a person's life is being threatened but in most cases, if it's more generally, they will be liable to be prosecuted and under the new law and will have no defense."

"It's not so much in case of abuse for a particular individual but for example, a teacher who works on Manus Island who then does an interview about the appalling conditions in schools or the level of hunger in kids. That person might feel a strong moral obligation to speak up but wouldn't be protected under this legislation."

Barnes said it will have a chilling effect and deter people speaking out.

"It's very clearly designed to stop the world from understanding the cruelty of the Australian detention centers."