Home Affairs Minister Peter Dutton says "advocate" doctors could be putting asylum seekers' names forward to be considered for medical transfer even if they haven't consented to it.
Mr Dutton says it is another flaw in the medevac legislation which came into force in March with the support of Labor and the crossbench and against the will of the government.
The minister has sought advice on a court challenge to another aspect of the laws - whether doctors determining medical transfer need to see a patient face-to-face or can merely review records.
A 29-year-old man from Iraq, who has been on Nauru for six years, sought approval for transfer to Australia under the medevac laws.
Two doctors formed their opinions and prepared reports for the Home Affairs secretary on the basis of the applicant's medical records and other material but did not personally interview or physically examine him.
The Home Affairs department argued the two doctors should have been required to personally assess the man but the Federal Court found this week a remote assessment of records was enough to meet the requirements of the medevac law.
Mr Dutton said the medevac legislation was a "deeply flawed process" and Labor needed to back the government to repeal it.
"As I'm advised not only do they not have to see the patient themselves the patient doesn't even need to provide consent," Mr Dutton told reporters in Sydney on Thursday.
"I'm not even aware that some of these people on Manus and Nauru know these advocate doctors are putting forward their cases for consideration."
Human Rights Law Centre senior lawyer David Burke rejected the minister's claim.
"Before doctors are able to make assessments, every patient provides their consent," he told AAP.
"This consent is needed for the doctors to obtain the patient's medical records."
Mr Dutton said if the bill wasn't repealed he would consider an appeal to either the full Federal Court or the High Court, on which he's sought advice.
"It's inconceivable that a sovereign government doesn't have the right to say who is going to come to our country and don't have the right for those people to return back once that medical advice has been provided."
Labor frontbencher Penny Wong said the minister did not understand the court decision.
"Nothing in this (court) decision changes or lessens the minister's power to reject someone coming to this country on health grounds, on character grounds or on national security grounds," Senator Wong told reporters in Adelaide on Thursday.
"On his watch, more people have actually been transferred to Australia from Manus and Nauru outside of the medevac process than through the medevac process."
Australian Associated Press