The Immigration Department has approved medical treatment on people in detention without their consent 10 times since 2005, including to force-feed a person on hunger strike.

A controversial regulation introduced in 1994 gives the secretary of the Immigration Department extraordinary powers that allow them to approve medical treatment on detainees – even if a detainee has expressly refused consent to the treatment – if they believe the detainee’s health is at serious risk on the advice of a medical practitioner.

Guardian Australia has obtained the two most recent applications under freedom of information laws, which date to May 2012 and November 2011. Both relate to people held in detention who had gone on hunger strike.

The treating medical doctor in November 2011 wrote that the detainee “needs IV fluid, dietician and feeding”.

“If medical treatment is not given to the detainee there will be a serious risk to his or her life or health; and further that the detainee fails to give, refuses to give, or is not reasonably capable of giving consent to medical treatment,” then secretary of the Immigration Department, Andrew Metcalfe, wrote in his approval of the treatment.

Protests regularly occur in the form of hunger strikes in detention centres around Australia and on Nauru and Manus Island. Last week asylum seekers on Christmas Island began a hunger strike in protest at the death of Reza Barati, the asylum seeker killed on Manus Island during unrest at the facility two weeks ago.

Mary Anne Kenny, the director of the Centre for Human Rights Education at Curtin University, said the regulation went far beyond the treatment that could be given to a person not held in detention.

“If there is a move to give you treatment in the community, you have to give consent. If you have treatment without consent it’s an assault, unless you’re incapable of giving consent or when you’re mentally incapable,” she said.

“The problem with this regulation is that it says that you can be given medical treatment in immigration detention regardless of consent.”

Kenny added that while hunger strikes in detention put medical practitioners in a difficult ethical situation, the regulation was a “blunt instrument”.

“They should not be treated any differently to anybody in the community. The fact they’re in detention does not mean the safeguards shouldn’t be there,” she said.

Medical officers have previously express concern about the state of medical treatment in detention centres. Fifteen doctors on Christmas Island wrote a scathing letter to the immigration minister, Scott Morrison, last year outlining their concern about the standards of care for people in detention.

The Immigration Department referred questions about the use of the power and what safeguards and guidelines were in place to the immigration minister.

A spokeswoman for the minister’s office said treating a detainee without consent “may only be done in circumstances where there will be a serious risk to the detainee’s life or health if they do not have the treatment”.

“The last time this occurred was under the previous government,” she added.

“Medical treatment includes the administration of nourishment and fluids, which must be undertaken in a hospital.”