The government has approved 31 medical transfers since the medevac law came into effect four months ago. As of Friday, nine refugees and asylum seekers had their applications rejected by the government - the medevac expert panel, reviewing the decisions, overturned two and upheld seven.

Due to a delay between the initial approval and a patient's treatment, 22 of the 31 approved have been transferred out of detention.

The transfer numbers - the first time such figures have been revealed since the medevac law passed - go against claims made by Mr Dutton that "floodgates" would open if doctors had greater power in deciding which refugees and asylum seekers could come to Australia for medical aid.

Under the medevac law, a bill which the Coalition opposed, an independent panel of expert medical professionals have the final say on all offshore detainees seeking mainland treatment, unless they pose a risk to national security or have a serious criminal conviction.

Any two licensed doctors can ask the panel to consider an offshore detainee's case.

Mr Dutton last week ramped up criticisms of the law ahead of the government's attempts to repeal the legislation when Parliament resumes in early July, saying the law gave doctors too much power.

"I do fear that this opens the floodgates ... it sends a bad signal when you have a country like ours being dictated by doctors who can say that people must come here," he said on Thursday.

The Home Affairs Minister also suggested the medical panel would side with refugees and asylum seekers.

"I think generally you would expect the medical review panel would overturn a minister's decision that refuted the original claim made by the two doctors."

Labor home affairs spokeswoman Kristina Keneally said in response that the expert panel was exercising restraint.

"In the past, the government has made ridiculous claims that hundreds of people would be transferred almost immediately to Australia because of medevac - that has not happened," the former NSW premier said.

Mr Dutton refreshed his medevac law attack following a Federal Court decision, handed down on Wednesday, that declared doctors need not make personal contact with refugees and asylum seekers on Nauru before recommending their case to the expert panel.

The ruling - which concerned a 29-year-old man from Iraq who came to Australia without a visa in 2013 and was taken to Nauru - was used by Mr Dutton to argue that doctors will have a far easier time referring detainees through the medevac system.

But medical professionals said the ruling brought the process in line with standard practice.

The government will seek to repeal the medevac legislation when it returns to Parliament in early July.

Following the federal election the government has the numbers to pass any repeal bill through the lower house, but could be denied by an all-powerful crossbench in the Senate if Labor continues to support medevac.

Returning Tasmanian senator Jacqui Lambie has emerged as the deciding vote on the legislation but has remained quiet about her vote intentions since being officially declared elected last week.

Mr Dutton's office was contacted for comment.