Firms warned to check waste disposal companies’ licences to avoid falling foul of rogue operators.

Businesses were warned yesterday to ensure they know how their waste is disposed of, after two men were given prison sentences for operating an illegal waste dumping company.

Chief executive of the Environment Agency (EA), Paul Leinster, said the case against Patrick Anderson and James Keller represented "the culmination of one of the most intensive investigations carried out by the EA in the illegal disposal of construction and demolition waste".

The men, who both pleaded guilty to the charge of conspiring to unlawfully deposit controlled waste on land, masterminded an elaborate illegal dumping operation in London and Essex between January 2003 and June 2004 that saw them dump 14,600 tonnes of waste at at least 15 different sites.

The EA said while sending out a strong warning to people who believe they can profit from illegal waste dumping, the case should also act as a warning to firms to ensure their waste contractors are disposing of their waste responsibly.

"Businesses and householders have a duty of care to ensure they hand their waste to an Environment Agency registered waste carrier," said a spokesman for the EA. He encouraged companies to phone the EA hotline or go online to check their waste disposal business is fully licensed and disposing of rubbish in an approved manner.

The NetRegs agency has also been working with small and medium-sized businesses to raise awareness of waste disposal, he added.

Anderson and Keller set up the illegal dumping locations as apparently legitimate construction sites, sometimes using fake company logos in the process.

"Financial investigations we carried out revealed that the pair had made approximately £1.2m from their activities, although not all of this would have been profit," said Owen Bolton, a senior environmental crime officer at the EA.

Arwyn Jones, national enforcement service manager at the EA, highlighted the organised criminal aspect of the work and said the EA is determined to tackle this serious crime to stop well-meaning businesses and individuals being misled.

About £340,000 has been spent on cleaning up the sites, with the taxpayer and private owners footing the bill, according to the EA.