Greens senator Nick McKim has accused Home Affairs Minister Peter Dutton or his office of leaking classified intelligence about border protection.

Federal police dropped an investigation earlier in the year into media reporting of Australian Security Intelligence Organisation advice about laws to make medical transfers for asylum seekers easier.

Senator McKim made the claim under parliamentary privilege on Tuesday as he warned Australia was going down a dangerous path to a police state.

"The leaking, which I have no doubt came either from minister Dutton or from his office to Simon Benson, a journalist at The Australian, of classified ASIO information," the Greens senator said.

He said the leak was condemned by ASIO head Duncan Lewis at the time it happened, but the Australian Federal Police "inexplicably" declined to investigate.

Mr Dutton's office has been contacted for comment.

He has previously denied his office was the source of the leak.

The February newspaper report detailed advice showing medical evacuation laws, which ultimately passed parliament against the government's will, would lead to the people smuggling trade restarting.

Senator McKim said the leak was one example of an erosion of rights, along with recent raids of the ABC headquarters and a News Corp journalist's home.

"You can understand why there is nervousness starting to emerge amongst our media, amongst journalists about the intimidatory nature of those raids," he said.

He said the coalition and Labor passed legislation under the cloak of national security and a powerful parliamentary committee in which the Greens don't have a say.