A nuclear expert from the University of Queensland and a conservative think-tank have been questioned over possibly misleading parliament over funding for his work.
Parliamentary officials, writing on behalf of the Labor-led committee looking into nuclear power, have written to adjunct professor Stephen Wilson to clarify his ties to the coal industry.
In response to questions from the ABC, Professor Wilson said he had not "personally" received funding from the "fossil fuel" sector for his work on nuclear power.
Professor Wilson gave evidence to the inquiry last month in his capacity as a nuclear expert with the Institute of Public Affairs, a conservative think-tank.
He has been regularly cited by the Coalition as an advocate for the technology, which forms the centrepiece of the Coalition's energy policy heading into the next election.
Professor Wilson travelled to North America with shadow energy minister Ted O'Brien on a nuclear study tour in 2023, including meetings with executives from nuclear giant Westinghouse.
He has also spoken at events with Mr O'Brien, criticising the current government's renewables-led energy approach and talking up the potential of nuclear power.
During the evidence Professor Wilson gave to the nuclear inquiry in October, he was asked if he had "accepted donations from the fossil fuel industry to fund your research on energy".
"No, I have not," he replied.
In a letter sent this week, officials have pointed to comments made by Professor Wilson in a speech delivered to an IPA event in mid-2023.
In a transcript of the speech, Professor Wilson describes his work with the IPA's energy security research program, and thanks donors for their support.
"I have taken on the challenge of working with Scott [Hargreaves] and the IPA staff, supported and encouraged by the far-sighted group of donors that Nick Jorss is bringing together," he said.
Mr Jorss is the executive chairman of coal miner Bowen Coking Coal, and chair of lobby group Coal Australia.
The letter seeks "clarification on what appears to be contradictory information on the issue of donorship".
The committee now questioning Professor Wilson was set up by the government in the House of Representatives to scrutinise nuclear power, which the Coalition has committed to ahead of the next election.
Professor Wilson has been cited by Opposition Leader Peter Dutton in speeches making the case for the Coalition's proposed pivot to nuclear power.
In a speech in July last year, Mr Dutton quoted Professor Wilson calling on Australia to "prepare real options to deploy nuclear energy … in case we need them."
The ABC contacted Professor Wilson with questions over the sources of his funding, and whether he had misled the committee.
In response, he denied having directly receiving funding from 'fossil fuel' sources for his work.
"I have not personally received payment from 'fossil fuel' companies for my research into the need for Australia to embrace carbon-free, nuclear energy," he said.
"I have advocated strongly for years, in my own capacity, for energy policy to be developed and implemented on a rational basis.
"As an energy engineer and economist with 30 years' experience in the economics and dynamics of energy systems around the world, and electricity and resources markets, I understand how vital it is for Australia to have energy security. Encouragingly, more and more Australians are starting to share this view."