The National Library of Australia's Trove database has been used to discredit Angus Taylor's claim he downloaded a doctored report about Clover Moore's travel from the City of Sydney council's website.
It has also been revealed the letter the Energy Minister sent to the Sydney Lord Mayor accusing her of virtue signalling was vastly different to the one drafted by the department.
Mr Taylor sent an "unreserved" apology to Ms Moore last month, after he falsely claimed the council spent $15 million on travel.
"Given your most recent annual report shows your council spent $1.7 million on international travel and $14.2 million on domestic travel, there is a real opportunity for your council to make a meaningful contribution to reducing Australia's emissions," his letter said.
He was allegedly relying on figures from the council's 2017/18 annual report, which his office also passed onto The Daily Telegraph.
But The Guardian revealed the report had been altered, and the real travel costs were around $6000.
Mr Taylor claimed there were multiple versions of the annual report on the council's website, and supplied a word document with different formatting by way of proof.
However Ms Moore said the website metadata showed the document had not been changed since it was uploaded.
During Senate estimates spillover on Tuesday, Labor senator Kristina Keneally said there was fresh evidence there was only one version of the report.
"Are you aware of Trove, the website run by the National Library of Australia?" she asked Minister representing the Minister for the Environment Minister, Simon Birmingham.
"What Trove does it archives websites, Australian websites and it just so happened Trove archived the City of Sydney website addresses for both the PDF and the word versions of the City of Sydney annual report 2017/18 on April 20 this year.
"Is it the minister's contention that the correct report was on the website on April 20 and replaced with a report with incorrect figures that his office downloaded on the September 9 and then the report with the correct figures was put back up again? Is that the contention of the minister?"
Senator Birmingham referred Senator Keneally back to Mr Taylor's statement that there was "clear evidence" of multiple versions of the report on the council website.
But Senator Keneally said the explanation was "implausible".
"Where did he get this document from. Did Godwin Grech bring it to him? Did fairies from the garden fly it in?" Senator Keneally asked.
Senator Birmingham said,"If you want to try stand-up comedy Senator, there are places other than senate committees for that."
Officials from the Environment Department also revealed public servants had drafted a letter for Mr Taylor that was very different from the one sent to Ms Moore.
The draft letter laid out the Coalition government's actions to address climate change and did not include the paragraph at the centre of the controversy.
The officials said the department did not provide the minister's office with any information about the City of Sydney's travel, and was not asked to verify any of the claims made.
A spokesman for Mr Taylor said he had nothing further to add to his explanation from last month.