TROY — A Castleton demolition company that was hired to tear down several buildings on King Street in 2013 pleaded guilty to violating the Clean Air Act and admitted that one of its employees had falsified federal documents by claiming asbestos was not present at the site.

The guilty plea to a misdemeanor charge by M. Cristo Inc., which is owned by Michael Cristo, follows a years-long investigation by the FBI and state attorney general's office that had also focused on the decision by city officials to order the buildings razed on an emergency basis.

The company's plea agreement indicates that a former employee, Ron Martin, falsified the federal document with the company's knowledge, and "intentionally assisted the employee in order to hinder and prevent their apprehension or punishment for the crime of making a false statement." Martin is no longer employed by the company, according to court records.

The King Street building the city ordered torn down in August 2013 under an emergency demolition order had been marked for demolition by both city code officers and its owner, who wanted to develop the parcel.

Former Councilman Mark McGrath subsequently filed a complaint with the state Department of Labor and said he saw dust spreading across the property and onto the adjacent Bombers Burrito Bar, which stayed open during the demolition.

The FBI subsequently intervened and began interviewing city officials about their decision to declare the structures unsafe and allow a controversial emergency demolition.

The demolition company, which is located on Kraft Road in Castleton, agreed to pay a $10,000 fine.

Cristo, the company's owner, referred comment to his attorney, John J. Privitera, who could not be reached for comment.

Martin was vice president and asbestos abatement supervisor for M. Cristo Inc. Court records indicate that Martin had been aware of the asbestos in the King Street properties several years prior to the demolition, including reviewing an asbestos survey of the properties.

The case against M. Cristo Inc. was prosecuted by the U.S. attorney's office in Buffalo because of an undisclosed conflict in the office of the U.S. attorney in Albany. A spokeswoman for the U.S. attorney's office in Buffalo last week declined to confirm whether the investigation is ongoing.

The properties — 4, 6, 8 and 10 King Street — had been owned by Columbia Street Associates of Albany, which is controlled by attorney Donald Boyajian, and had a market value of $140,000, according to prior published reports.

Boyajian on Friday said he was unaware of the plea agreement by M. Cristo. Boyajian previously said that he had not requested an emergency demolition for the properties. Cristo was on a list of contractors kept by the city and city officials called him with Boyajian paying the bill.

The investigation of the situation has languished. In 2014, the Times Union reported that the FBI interviewed city Engineer Russ Reeves about the decision by Bill Dunne, the city's commissioner of planning and economic development, and Fire Chief Thomas Garrett to order the buildings knocked down.

Dunne and Reeves left their jobs with the city a few years ago.

John Salka, a spokesman for Troy Mayor Patrick Madden, said Friday that city officials had not been aware of the demolition contractor's plea and have not had any recent contact with law enforcement agencies that probed the incident.

The demolition of the King Street building, which survived Troy's Great Fire of 1862, came the day after Reeves left the state for vacation. He told the Times Union several years ago that he had no knowledge that Garrett ordered the razing.

The day the buildings were demolished — Aug. 5, 2013 — the fire department had identified a three-story, wood-frame, yellow row building at the site as being too dangerous for firefighters to enter in the event of a fire. Garrett then ordered it to be torn down.

The emergency demolition may have saved tens of thousands of dollars in asbestos abatement costs, but also created controversy because some onlookers were worried about the dust cloud that followed.