Methane bubbles in the Condamine River, west of Brisbane, appear to be spreading to new areas and are becoming more intense, the footage supplied by Lock the Gate Alliance shows.
The group claims nearby coal seam gas activity has "enhanced" the amount of methane escaping in the area, despite reassurances from gas companies that the issue had been mitigated.
Local activist Dayne Pratzky, who brought attention to Condamine methane bubbles a decade ago, says he holds serious concerns about the amount seeping into the area.
"New areas of the river are now bubbling like a boiling broth, much closer to the Chinchilla Weir than impacted areas of the river first identified about a decade ago," he said.
Last year, a Queensland state regulator report recommended a new watchdog after a probe into the impacts of subsidence on the plain, west of Toowoomba.
The regulator said existing protections, and dispute and compensation processes, needed to be clarified and strengthened for landholders and gas companies.
A 2021 report provided to the state government found coal seam gas activity in the region had "enhanced" methane escaping in the area, but the more serious seeps had been mitigated.
"While the seeps are a natural system, the gas escape is enhanced by down-dip CSG production, which is approximately 1km away," the report said.
"The Condamine seeps were mitigated by reducing the pressure in the underlying traps through gas production combined with increased CSG production to capture more of the gas.
"The seeps do however highlight that migrated free gas may not necessarily be reabsorbed onto the coal quicker than the rate at which it migrates."
Activists claim their footage has serious implications for a safeguard mechanism between the Queensland and federal government.
"The safeguard mechanism will require emitters to reduce their net direct emissions year on year," Ellie Smith from Lock the Gate said.
"But this will be extremely difficult to monitor and enforce when gas activity is increasing the rate of methane coming out of the ground in areas beyond the immediate gas field.
"Governments cannot approve any new gas fields if we are to stand a snowflake's hope in hell of avoiding climate catastrophe, particularly when, as this new footage shows, the true extent of fugitive methane emissions is not properly understood."
Comment is being sought from Origin Energy, which operates coal seam gas exploration for Australia Pacific LNG in the Surat Basin, which covers the Condamine River.
