A request for Queensland police to cease their investigation into leaked state Cabinet documents used in a series of news stories by ABC Brisbane, will be made by the journalists' union the Media, Entertainment and Arts Alliance.

Police carried out a search warrant at the South Bank office following a complaint by the Queensland Cabinet Secretary Leighton Craig that the documents may have been "improperly accessed" in breach of Cabinet rules.

A police officer from the Queensland Police State Crime Command executed the warrant during a visit to the organisation's Queensland headquarters on Wednesday afternoon.

The warrant said that a "person or persons unknown, having been employed in public office by the Queensland Government, unlawfully communicated information, namely confidential Cabinet briefing notes and internal government savings proposals by the Liberal National Party in 2012 … that was his or her duty to keep secret".

The stories, by ABC National Reporting Team journalists Mark Willacy and Alexandra Blucher, focused on deep budget cuts to Queensland's environment department under the then LNP government of Campbell Newman in 2012.

The stories were based on a raft of leaked Cabinet briefing notes and internal savings proposals.

One Cabinet note revealed the LNP government used a "pain ranking" to help decide which programs and budgets would be slashed, while another detailed how oversight of the controversial coal seam gas industry was repeatedly cut.

A third story in the series revealed the former Newman government killed off a profitable climate change company run by the state.

MEAA Queensland director Michelle Rae said the police investigation into the ABC impinged on the right to free press and the community had a right to information.

"It is a journalist's job to let the community know important information, and sometimes that can be embarrassing for political leaders," she said.

"When it is embarrassing they have to stand up and then answer the questions that the journalism raises."

She said the union was seeking clarification into where the original complaint came from.

"From the MEAA's perspective we will be writing to the cabinet secretary and the Attorney-General seeking clarification as to who triggered the complaint," she said.

No idea police would take action, Tim Nicholls says

LNP leader Tim Nicholls, who was Queensland treasurer at the time the documents relate to, said the Opposition was told action would be taken after it raised concerns with the Premier's Department when the original ABC story was published.

But Mr Nicholls told ABC Brisbane today that he had no idea that police would move yesterday.

"That was entirely a decision of the Queensland Police Service — of course we have no influence in respect of their actions," Mr Nicholls said.

"When these documents first came to light, we raised the issue with the head of the Premier's Department as to how these documents had managed to come to light, given that they are protected Cabinet in-confidence documents ... protected as all Cabinet deliberations are.

"This goes to the heart of decision making by governments and that is in relation to the confidence of Cabinet discussions, and there's a long established Westminster and parliamentary tradition here in Queensland that cabinets make decisions.

"If they're not free to consider all options and to have robust discussion around the Cabinet table, then decisions don't get made."

Mr Nicholls said he had no further involvement after asking the director-general of the Premier's Department during budget estimates hearings in July about what was going on.

"I don't know that it was a complaint — I think we raised the issue and said look, we're concerned to see that Cabinet confidence has been breached," Mr Nicholls said.

"I think the director-general acknowledged our concerns and said that he would take action."