GRINDSTONE, Maine — Anti-gay epithets left at the scene of a fire that destroyed a Grindstone Road cabin this past weekend will be investigated by the Maine attorney general’s office as a possible civil rights violation, officials said Monday.

The investigation into the fire continues and no determination of its cause has been made, but Sgt. Tim York of the Maine state fire marshal’s office said Monday that he immediately referred the matter to the attorney general’s office for investigation.

“We have received that notification,” said Brenda Kielty, a special assistant to Maine Attorney General William Schneider, “and this office would be responsible for investigating any incident that might be a civil rights violation.”

The epithets were spray painted in large black letters on the front of a shed and on what looked like part of a roof of a smaller structure near the remains of the cabin, which is on the Penobscot River. No one was injured in the fire, and the camp’s occupants were not there but might have been earlier in the day, East Millinocket firefighters said.

A 911 call reporting the fire came in at about 12:07 a.m. Saturday. Neighbors reported that they had heard an explosion. When the first East Millinocket firefighters arrived around 20 minutes later, the roof of the one-story structure had collapsed and flames were demolishing the rest of the building, firefighters said.

Efforts by the Bangor Daily News to contact the camp’s occupants since Saturday have been unsuccessful. One of their neighbors, John Coon, said the spray-painting of the slurs was “hard for me to believe.”

“It’s too bad,” Coon said. “I have met one of the guys several times. He is a very nice, friendly guy.”

The Grindstone Road property was put up for sale about a month ago, said real estate agent Alice Weed, who is handling the sale effort. The owners have also put their Millinocket home on the market.

Coon said they “did a lot of work on it [the property] over the summer,” apparently hiring a contractor. The work appeared to make a huge improvement on what was a somewhat dilapidated structure, he said.

Given the struggling real estate market in the Katahdin region, it would have been “a tough sale but not impossible,” Weed said. “It was a nice house.”

Twelve Medway Fire Department firefighters and two tanker-trucks assisted the East Millinocket firefighters who covered the blaze, Medway Fire Chief John Lee said. Five East Millinocket firefighters responded. Both towns cover Grindstone through contract or by mutual-aid agreement.

It was unclear whether the explosion ignited or resulted from the fire.