(Bloomberg) — UK energy regulator Ofgem announced an international audit of Drax Group Plc’s sourcing of the biomass used in its power plant.

The audit will include suppliers and third parties across Canada, the US and Brazil, and will examine the carbon intensity associated with the company’s biomass supplies.

Ofgem said that Drax — which appointed the auditors — agreed to the process as part of a £25 million ($34 million) settlement last year, when the company accepted that there were inaccuracies in some of the data it reported. The audit, the largest such exercise ordered by Ofgem, will focus on 2023-24 and include most of Drax’s global supply chain.

“Ofgem will not hesitate to take appropriate action if it reveals any compliance issues,” Neil Lawrence, Ofgem’s director of delivery and schemes, said in a statement. “The onus is on Drax” to show that it now complies with its legal obligations, Ofgem said.

The company has faced criticism over the green credentials of the wood that fuels its main power station in northern England, with the Financial Conduct Authority launching a separate probe in August. The government earlier this year agreed to new subsidies to keep the plant running, but with restrictions.

Forvis Mazars will conduct the audit; it’s expected to start work by the end of September and take up to 18 months on the assignment.

“We fully support this independent external audit process, working with Forvis Mazars and Ofgem, to add further rigor and transparency to our profiling data reporting,” Drax said.

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