Laundered diesel is costing the public purse as much as ¤150m every year, retailers said.
They demanded tax reforms and more resources for gardai and customs officials to fight the illegal trade.
Frank Gleeson, chairman of representative group Retail Ireland, told the Government rising fuel prices are encouraging even more laundering.
"Recent import figures would suggest that at least 12pc of all diesel sold in Ireland is illegal," he said.
Plastic chemical 'harms children'
Exposure in the womb to bisphenol-A, a chemical used to make some plastic containers, may cause behaviour and emotional problems in young girls, a study found.
The research showed that hyperactive, anxious, aggressive and depressed behaviour was more common in three-year-old girls who were exposed in the womb to bisphenol-A than in boys of the same age.
No association was seen between bisphenol-A levels during later childhood and behaviour, according to the study released by the journal Pediatrics.
Woman taken ill at South Pole
A sick American woman who was evacuated from the South Pole to New Zealand said she is making her way back to the United States.
Engineer Renee-Nicole Douceur said she has left New Zealand and landed in Australia.
She will pass through San Francisco and Washington before arriving at Johns Hopkins Hospital in Baltimore.
Cancer patients can't afford food
Cancer patients are forced to cut back on buying food and other everyday essentials as a result of their disease, a UK charity warned.
One in six patients is hit due to increasing costs and lost income, Macmillan Cancer Support said.
A survey also found some patients are skipping meals to help save money, while others are scared of losing their home.
The poll of 1,495 patients said 70pc are hit financially by the disease.