The U.S. Occupational Safety and Health Administration is scrutinizing how Nevada officials conducted a 2007 investigation into the remodeling of the Flamingo Las Vegas hotel and casino, which exposed workers, and possibly guests, to airborne asbestos, the Las Vegas Review-Journal reports.

Federal OSHA officials are trying to determine whether their counterparts at Nevada OSHA understated the extent of the contamination to help the casino’s corporate owner — Caesars Entertainment, formerly known as Harrah’s Entertainment — minimize its potential legal liability.

The federal review stemmed from a written plea by Chuck Gillenwater, a carpenter who worked at the casino, to U.S. Rep. Walt Minnick, D-Idaho. Gillenwater asked Minnick for help after state officials rejected his complaint that the 2007 state investigation was inadequate.

The crux of Gillenwater’s complaint is that Nevada OSHA in 2007 played down the extent of the asbestos contamination, even though it upheld three safety violations. A year earlier, Harrah’s Las Vegas, a sister property, completed remodeling that led to similar violations. Yet Nevada OSHA did not classify the Flamingo exposures as repeat violations, which can increase the fines.

Among other things, Gillenwater complained that workers at the casino spread asbestos fibers outside the Flamingo’s containment zones when they hauled demolition debris through the building out to dumpsters. Asbestos, which has been used in a variety of building materials, can scar the lungs and cause cancer when breathed.

According to a federal OSHA summary of the complaint, “asbestos-containing materials [were] tracked into the employee dining area, kitchen bakery area and elevators.” As a result, the complaint said, the hotel’s maids, room service staff and possibly guests — those who went near work zones or the trash-removal route — were exposed to asbestos.

Gillenwater told the Review-Journal he would not comment on the investigation until it is complete. A spokeswoman for Caesars Entertainment also declined to comment, saying the company has not been notified by federal OSHA officials about their review.

The federal agency opened its office in the area after Congressional hearings last year into a rash of workplace deaths in Southern Nevada, including hotel construction accidents.