Customs officers dismantled and shut 22 fuel laundering plants in Northern Ireland this year which were capable of depriving the Inland Revenue of £68 million in taxes.
The 94,000 litres of toxic sludge dumped by criminals involved in the illegal operations was enough to fill 500 domestic wheelie bins, according to HMRC staff.
It costs an estimated £1.13m in public funding to dispose of the waste.
New details were disclosed as senior officials warned there would be no let-up in 2013 in the crackdown against the gangs involved, mostly in the border regions.
Pat Curtis, national oils co-ordinator for HMRC, said: "Laundered fuel is sold at a reduced price and motorists may think they are getting a good deal because it is cheaper. But I would caution them to think again as the true cost is far from a bargain for anyone.
"We will continue to carry out raids and roadside checks to detect those attempting to smuggle, launder, sell or use illicit fuel. We are all losing out."