The biggest power station in Britain - which burns millions of tonnes of imported wood pellets, categorised as a green source of renewable energy - has found itself accused of environmental damage.
The investigation found that wood for its pellets was sourced from primary forests in Canada, including areas that had taken thousands of years to develop.
Here is everything you need to know about it.
What did the investigation find?
Panorama used satellite images, logging licences, and drone footage to back up its findings. Reporter Joe Crowley also followed a truck from a Drax mill to verify it was removing whole logs from a protected area of forest.
Ecologist Michelle Connolly told Panorama that the company was destroying forests that had grown over thousands of years.
UK taxpayers provide the company with billions of pounds in green energy subsidies, and Connolly said it was “really a shame” that British taxpayers are “funding this destruction with their money.
“Logging natural forests and converting them into pellets to be burned for electricity, that is absolutely insane,” she said.
Panorama discovered Drax purchased logging permits to clear two areas of environmentally significant forest in British Columbia.
One of the Drax forests is a square mile in size, with vast portions of rare, old-growth forest; the British Columbia provincial government says these forests are especially valuable from an ecological standpoint, and that firms should refrain from logging them.
The Drax power station is a converted coal facility that now generates 12% of the UK’s renewable energy, though how ‘green’ its wood burning practices are is controversial among environmentalists.
Burning wood pellets emits more greenhouse emissions than coal burning, but Drax’s source of energy is classified as renewable because new trees are planted to replace old ones.
Since these new trees are expected to absorb the carbon generated by burning wood pellets, it is considered a green source of electricity by many authorities, but recapturing the carbon can take decades, and offsetting only works if the pellets are generated from sustainable sources of wood.
Primary ‘old-growth’ forests contain massive amounts of carbon and have never been logged before. They are not regarded as a sustainable source, and any replanted trees will almost certainly never capture as much carbon as the previous forest.
Where is Drax power station?
Drax power station is located near the village and civil parish of Drax in North Yorkshire, about six miles south-east of Selby. The power station itself is situated on the River Ouse between Selby and Goole.
Who owns Drax power station?
Though the power station’s name derives from the nearby village of Drax, the facility is owned and run by Drax Group PLC.
Founded in 2005, the company has attracted numerous controversies over the years, including a 2020 “virtual protest" held by campaigners in response to claims that Drax is the UK’s largest emitter of carbon dioxide, and that the wood pellets Drax burns are leading to the destruction of forests.
Protestors also claimed that the company is burning more wood than any other power station in the world.
What has Drax said?
Drax told Panorama that many of the trees in the protected areas of forest had died naturally, and that logging them would lower the risk of wildfires.
The company told the BBC that it had not cut down the trees itself, and had instead transferred the logging licences to other companies. However, Panorama confirmed with the British Columbia authorities that Drax still holds the licences.
Drax stated that it did not use logs from the disputed sites identified by Panorama to make its wood pellets. Instead, the logs were transferred to timber mills to be utilised in the production of other wood goods, with the company using only the residual sawdust from these processes for its pellets.
According to the corporation, certain logs are sometimes used to manufacture wood pellets, though these are only small, twisted or rotten - ‘low grade’ logs - which cannot otherwise be used for wood products.
However, documents from a Canadian forestry database show that only 11% of logs transported to two Drax plants in the previous year were categorised as low grade.
The company also stated that the Panorama-identified logging spots were not within primary forest sites since they were near roads, but the UN’s definition of primary forest does make mention of road proximity. One of the sites found is six miles from the nearest paved road.