The Environment Agency says it is tracking movements from land where there is a 2,000 ton mountain of waste.
The rubbish has been growing at the Rowanoak Waste site on Shaw Road for more than two years.
The Environment Agency told the landowner to clear the waste by last September, but it is still there.
Local business owners, like Bob Swallow from Midtherm Powder Coating, says it is causing them problems with dust.
Dudley North MP Ian Austin says he wants quicker action from the Environment Agency.
The agency claimed a fortnight ago that those responsible for the site had finally started removing the waste, but Ian says only a tiny amount has been shifted and work has already stopped.
In response, West Midlands Police said the rubbish was being dealt with by the council and Environment Agency.
Dudley Council said it was an issue for the Environment Agency and not themselves.
The Environment Agency said:
Our reporter Mark Gough rang the telephone number on the sign of the site but it was dead, and he shouted through the gates to speak to the one person who was on the site but he did not respond.
The company which owns the land and the waste company share the same registered address in Brierley Hill but we were unable to speak to anyone.