Car dismantlers across the city have been targeted in a Government crackdown on illegal scrapyards.

Officers from the Environment Agency made spot checks at 28 scrapyards in Bradford to see whether they were complying with new pollution laws.

The legislation, which came into force earlier this year, means that all companies who scrap cars must take out polluting substances such as oil, petrol or batteries before they are sent to be crushed. And cars must be dismantled on an impermeable surface, such as concrete, so that oils do not seep through and contaminate the ground.

Inspectors found 21 of the dealers visited did not comply with the new rules and a further six were actually operating illegally without a licence. Ian Cowie, environment management leader for the agency said: "This new legislation won't make any practical difference to householders, but we are taking it very seriously from an enforcement point of view.

"All sites that didn't comply with the regulations were served with a notice giving them four weeks to get up to scratch. If they don't comply within this timescale we could suspend their licence or even stop them from operating. Ultimately sites that continually fail to comply with the law could end up in court, face a hefty fine or even go to jail."

Mr Cowie said his team had collected evidence against the scrapyards who were operating without a licence and had handed this over to the agency's solicitors who would be taking legal action. When the law change was brought in, campaigners suggested scrapyards may refuse to take certain cars due to the increased cost of disposing of them in line with the legislation, resulting in hundreds of cars being dumped on the street.

But Mr Cowie said the value of scrap metal was high at the moment and it was worth dealers taking it.

Roy Towriss, 62, who owns the licensed Springfield Auto Spares in Idle, said: "These new laws will improve the environment in the long run, but people who are bringing their motors in will have to bear the costs.

"We will always take scrap metal in. There may be a charge to the customer but if people don't panic the situation won't be too bad."

Anyone illegally disposing of cars should be reported to the Environment Agency free and in confidence on 0800 80 70 60.