The 2013 event was held in the boardroom of ERM Power, one of many meetings between the minister, the energy company and lobbying firm SAS Group, according to documents seen by Fairfax Media.

A spokesman for Mr McArdle said the minister always complied with the reporting obligations set down by Premier Campbell Newman's demand for the most transparent and accountable administraton in Queensland's history, but the boardroom fundraiser did not fall into the category of a reportable event.

"Fundraising is carried out by the party organisation in strict compliance with state and federal laws," the statement says.

A spokesman for ERM Power said political fundraising was a "legitimate exercise of the freedom of political association and expression".

"ERM Power complies with the regulatory framework in Queensland for such activities, making the required disclosures under the Electoral Act," he said.

The documents, which the Electrical Trades Union is expected to submit to the Senate Inquiry in to the Queensland Government, show meetings and meals between the government, ERM executives and their lobbyists stretch back to 2012, soon after the LNP took office.

Locations included Minister McArdle's office, the LNP state conference and the Queensland Club.

Mr McArdle's spokesman said the minister regularly met with a wide range of stakeholders in the energy and water sectors.

Among the meetings this year:

• Mr McArdle met ERM Power representatives at The Queensland Club on February 5 to discuss "renewable energy" on February 5;
• The state government [re-] announced changes to the solar feed-in-tariff on March 6, changing the 8 cent solar FIT paid to 40,000 Queenslanders to a system where customers negotiated directly with retailers; and
• On March 11 Mr McArdle was the guest at a lunch hosted by SAS Group in the lobbying company's boardroom. 

SAS Group did not declare the event on the contact register maintained by the state's Integrity Commissioner but Mr McArdle did, listing its purpose in his diary as "boardroom lunch" and naming the lobbyists as the organiser.

The documents, obtained under right to information laws, reveal Mr McArdle was the guest speaker.

SAS Group chief executive Peter Costantini said the 11 March lunch was not an ERM event and did not need to be declared.

"This was not a lobbying activity as defined by the Act, and we are confident that we have fulfilled all of our obligations," he said.

Mr Costantini said there was no unusual relationship between his lobbying company, its client and the government.

"The SAS Group is proud of the wide networks we have across the political spectrum and work we do for our clients and for the benefit of the state," he said.

Since its launch in 2008, ERM Power has grown to become the fourth largest electricity retailer (by volume) in the National Electricity Market.  It sells to the business sector, which equates to about 70 per cent of all the electricity sold across Australia.

Fairfax Media last year revealed that ERM, which had previously predominately donated to the Labor Party, had donated more than $25,000 to the LNP since 2010, with $1500 going to the Labor Party in the same period.

The government appointed the company's non-executive chair, Tony Bellas, as head of its Independent Review Panel into the electricity sector in May 2012.

An ERM Power spokesman said the company, whose Brisbane office was opened by Premier Campbell Newman in April 2013, was a major Queensland employer and ASX listed entity and as a matter of good business practice maintained appropriate relationships with all of its stakeholders, including the government and opposition.

The Senate Inquiry into the Queensland government will hold its next public hearing on November 28.