State environmental officials say they are investigating possible illegal dumping sites or operations in Holtsville, Cutchogue and Bay Shore.

The agency is also working with Brookhaven Town, which has issued a stop-work order at a tree-cleared building lot in Holtsville where mounds of dirt and soil are present.

And Islip Town officials sent fire marshals to investigate an industrial parcel that has been home to demolition, hauling and construction operations.

The actions were all spurred by an anonymous email widely sent to municipal officials and members of the media, alleging a vast conspiracy to mix concrete, asphalt, wires, dirt and other compounds and sell it as clean dirt, as well as to illegally dump materials throughout Suffolk County.

“We received multiple tips and are actively working with the town of Brookhaven to investigate these issues,” Department of Environmental Conservation spokesman Sean Mahar told Newsday.

The state probe includes examining records and site information but Mahar could not disclose more because of the ongoing nature of the investigation.

advertisement | advertise on newsday

On Monday, Brookhaven Town officials issued a stop-work order at a vacant lot along Blue Point Road in Holtsville that is adjacent to two newly built homes.

Town Attorney Annette Eaderesto said summonses will be filed in District Court in Patchogue against the owner of the lot, Manuel Esteves, as soon as they confirm his address. The charges include illegal dumping, burying of trees and trespassing on town property, spokesman Kevin Molloy said.

Brookhaven will also seek access to the property and, if allowed, work with a geologist to examine the site and determine whether any contaminants are present.

“It looks like there was some fill brought in,” Eaderesto said. “The town takes this very seriously. We will pursue this.”

Esteves could not be reached for comment.

In Bay Shore, fire marshals went to a site on Harrison Avenue and Islip Town officials are awaiting results of the evaluation, spokeswoman Caroline Smith said.

The email also mentioned a site on Cox Lane in Cutchogue. Further details were not immediately available.

The probes come amid renewed attention to illegal dumping on public and private lands on Long Island, from small cases to more sophisticated operations where construction and demolition debris is ground into fine particles and made to look like dirt or mulch.

Last week, a state Supreme Court judge sentenced two men in connection with dumping tens of thousands of tons of contaminated construction debris at Roberto Clemente Park in Brentwood, a small subdivision for veterans in Islandia, a wetland in Deer Park and a small plot in Central Islip.

Brookhaven Town last month won an injunction against the owners of three Manorville parcels from importing dirt, gravel, construction and demolition debris and other items to their properties. The town, which claims the properties hosted illegal solid waste facilities, also won access to inspect, sample and investigate compounds found on the properties.