Satellite images reveal how a grassy field in Oxfordshire was transformed into an illegal waste site in just a few months.
The site is next to the A34, a busy road running through cities including Oxford and Birmingham.
The land is just over three acres in size and is largely hidden by trees on all sides. The River Cherwell runs along its west side.
A satellite image from the end of March this year shows the site largely covered in grass.
By 13 June, it has completely transformed. The grass is replaced by dirt, and an excavator is caught in a satellite image.
On 17 August, the site remains largely unchanged apart from what appears to be a single lorry load of rubbish.
Five weeks later on 22 September, a 150-metre long and 15-metre wide area is piled with waste.
Drone footage filmed by Sky News shows that the waste dump is at least 10 metres high.
It would have taken tens of lorry loads to pile up this much waste in so little time.
Calum Miller, Liberal Democrat MP for Bicester and Woodstock, told Sky News it was the first time he had seen anything on this scale, questioning whether the Environmental Agency had the resources to deal with it. He said it's the work of an organised crime group.
The cost of removing the waste is estimated to be more than the entire annual budget of the local council, which is around £25m.
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With the site on a floodplain, Mr Miller listed what he saw as the three major environmental risks - waste being washed into the waterways, rain seeping through the waste and carrying toxins into the water and the danger of decomposing chemicals presenting a fire risk.
He said the police had used a helicopter with a heat-seeking camera and could see that some of the waste was indeed starting to decompose.
The crime costing the economy billions
Sky News has been investigating how, across the country, waste crime is a growing scourge and a booming business being exploited by criminal gangs.
Being paid to remove rubbish only to dump it illegally without sorting it or paying tax is an easy way of making huge amounts of money, with poorly enforced legal repercussions and a huge cost to the environment.
It's something the previous head of the Environment Agency called "the new narcotics".
- It's thought a fifth of all waste in England is being illegally managed
- That's around 34 million tonnes a year, enough to fill about four million skips
- It costs the economy around a billion pounds a year, with legitimate operators thought to be losing a further £3bn from missed business
In July, we tracked down a group of suspected organised fly-tippers who waved wads of cash on TikTok after dumping waste in the countryside.
The Environment Agency told Sky News it has obtained a court order to close the site to all public access for at least six months. The land appears to have been unused for years.
A spokesperson said: "Specialist officers are investigating waste dumped near the A34 at Kidlington. Their role will be to find who left the waste there and take appropriate action.
"We share the public's anger about incidents like this, which is why we take action against those responsible for waste crime," asking anyone with information to call their 24-hour incident hotline.
The Data and Forensics team is a multi-skilled unit dedicated to providing transparent journalism from Sky News. We gather, analyse and visualise data to tell data-driven stories. We combine traditional reporting skills with advanced analysis of satellite images, social media and other open source information. Through multimedia storytelling we aim to better explain the world while also showing how our journalism is done.