The Greens are pushing for an investigation by the independent Auditor-General into allegations Australia’s benchmark emissions offset scheme is being rorted, as the government rejected “any assertion” of fraud.

Senator Peter Whish-Wilson, from Tasmania, said it was essential Australians have confidence in the carbon market, which involves the Clean Energy Regulator issuing Australian Carbon Credit Units (ACCUs) to farmers who create carbon sinks or other forms of land-based abatement, using billions of dollars in public money.