A suspected fuel laundering plant has been dismantled and one man arrested following an investigation by customs officers.
HMRC workers, supported by Durham County Council, searched an industrial site and nearby home in the West Durham area earlier this week.
Suspected fuel laundering equipment was seized along with 1,700 litres of fuel and an estimated £10,000 in cash.
A 45-year-old man from County Durham was arrested.
It is believed the plant could produce up to 1.2 million litres of illegal fuel each year with a potential tax loss of £800,000 per year.
Denis Kerr, Assistant Director, Fraud Investigation Service, HMRC, said: “The production and trade of illicit fuel is a serious crime.
"It is dangerous, harmful to the environment, and steals money from public services such as hospitals and schools.
“I would urge anyone with information about the production or trade of laundered fuel to contact us online or call our Fraud Hotline on 0800 788 887.”
Joanne Waller, Durham County Council’s head of environment, health and consumer protection, said: “People who supply illicit fuel are avoiding the taxes that law abiding businesses pay and we will not tolerate such practice in County Durham.
“This investigation came about as a result of intelligence received from close working relationships across agencies and the action taken is a great example of what can be achieved through partnership working.
"We hope it will serve as a deterrent to anyone who might be tempted to enter this illegal trade.”
The man arrested has been released pending further enquiries.
Investigations are ongoing.
Information about any type of tax fraud can be reported to HMRC online at https://www.gov.uk/report-an-unregistered-trader-or-business.