CSIRO accused of transparency failures over Santos Darwin gas leak, documents show

Internal CSIRO messages released under freedom of information laws show the national science agency worked to manage scrutiny of its role helping gas giant Santos investigate a methane leak that ran for 18 years at the Darwin LNG plant.

The documents, released to the Environment Centre NT (ECNT) under FOI, show staffers sent emails and internal messages revealing discomfort with the scrutiny that followed the ABC's reporting on the leak last year. One staffer working on a response to the ABC wrote: "difficult and tricky — for us too with the minister. god damn it."

Staffers discussed how some of their responses could be more "fulsome", and went to lengths to note the agency's work did not include direct monitoring of the leak, while acknowledging internally that CSIRO's contract with Santos allowed for direct monitoring.

The ABC revealed in September 2025 that the LNG storage tank at Santos's Darwin plant had been leaking methane into the atmosphere after damage it incurred during commissioning in 2006. The estimated release of nearly 100kg an hour was just shy of what would count as a super-emitter under US regulations. The revelations were widely reported as contributing to the collapse of a $36 billion takeover bid for Santos.

The reporting also revealed that a number of state and federal agencies, including CSIRO, had knowledge of the leak. None of them made it public, or informed other government agencies that were considering approving Santos's application to use the damaged tank for decades beyond its planned life. Santos has since been approved to continue using the tank for another 20 years, an outcome the reporting links to the company's development of the controversial Barossa gas field off the north coast of Australia.

The FOI documents show how the scrutiny played out inside CSIRO and between the agency, the minister and the Department of Industry, Science and Resources (DISR), which oversees it. In one explanation to DISR, CSIRO said: "In 2024, CSIRO was engaged by Santos to undertake monitoring of the Darwin LNG project site." At another point a draft response was edited, with a staffer noting: "I suggest adding wording to reinforce it was 3rd party methods we reviewed to be crystal clear we didn't do any monitoring."

As staff drafted a public statement responding to the ABC story, one staffer shared the agency's contract with Santos. A reply read: "perfect — that's pretty clear… says we can do monitoring… but we didn't." One staffer then asked: "are you going to send our statement to your mate?" A staffer responded: "All good — I sent to their media chap this morning."

A CSIRO spokesperson told the ABC the agency developed and approved its own media response, and that a copy of the statement was provided to Santos as a courtesy. In its published statement, CSIRO said the work "did not involve monitoring, prevention or remediation advice related to the leak". The final published response said it was correcting "errors" in the ABC report, but no errors were identified in the statement.

The FOI documents confirmed the agency knew the size of the leak, with staffers noting it was estimated at 97.6kg an hour. When staffers discussed how to respond to questions from then-Greens leader Senator Larissa Waters, one asked: "Do we take the opportunity to be a bit more fulsome and include the work?"

Bree Ahrens, acting executive director of the ECNT, called on CSIRO to open its books. "These documents suggest to us an ongoing and frankly unacceptable reluctance on behalf of CSIRO to be transparent with the public," she said. "The only way to resolve these unanswered questions is to put the full set of data and the review on the table for the public to consider."

Former NSW Supreme Court judge Anthony Whealy said there was a "distinct impression given that CSIRO have not been entirely frank and open in relation to their dealings in this matter". "They are a public agency and we should expect them to be open with us. I think the public expect that and the media expect that as well," he said.

The CSIRO spokesperson said the agency's concern was "that the article conflated CSIRO's work assessing background methane concentrations and a desktop review of third-party methane measurement methods with advice relating to management of the reported leak. CSIRO did not provide monitoring, remediation or leak-management advice." On the drafting process, the spokesperson said: "As is normal when developing responses, different levels of detail and draft formulations were considered. The final statement reflected the information considered necessary to accurately explain the nature and scope of CSIRO's work."

A Santos spokesperson told the ABC the company developed a "leak detection and repair program" in 2025. "This program is aimed at finding and mitigating any potential fugitives within the facility. This measurement and monitoring will further enhance reporting of fugitive emissions," the spokesperson said.