The deaths of four young adults whose bodies were discovered Friday night in a remote cabin in Oxford County are still under investigation, but the law enforcement officer in charge of the case believes that the two men and two women were victims of carbon monoxide poisoning.

Oxford County Sheriff Wayne Gallant said Monday that the state medical examiner’s office is in the process of conducting autopsies on the bodies of Brooke Wakelin, 21, and her boyfriend, Keith Norris, 23, both of Attleboro, Massachusetts; and Wakelin’s brother, Matthew Wakelin, 18, and his friend Deanna Lee Powers, 22, both of Mansfield, Massachusetts.

Their bodies were found in a cabin in the town of Byron on Friday night by the Wakelins’ father, Mark Wakelin of Braintree, Massachusetts, who had come to the cabin to celebrate his daughter’s 22nd birthday and his son’s graduation from Mansfield High School, according to the Quincy (Massachusetts) Patriot Ledger newspaper.

“I think some of the telltale signs of carbon monoxide poisoning will be evident,” Gallant said of the pending autopsies. “Based on what we saw, everything points to carbon monoxide poisoning.”

Gallant said the medical examiner’s office has not yet ruled on the cause of the deaths, but he said the process should be complete soon.

In addition to the four people who died, a beagle that was in the cabin also perished.

Gallant said the four young adults had arrived at the cabin, which is owned by the Wakelins’ father, last Tuesday. They plugged the refrigerator into a generator, which had been stored in the basement, to prevent their food supplies from spoiling, Gallant said. The cabin is off the electrical grid.

“They should have put the generator outside the cabin. You never run a generator inside,” Gallant said.

Gallant said the four people likely died Tuesday night or Wednesday morning.

The cabin is located on Bateman’s Lane, a winding dirt road that runs along the east branch of the Swift River. It is relatively secluded from other cabins on the river.

Investigators said the generator was in the on position when they arrived, but it had run out of gasoline.

Mark Wakelin discovered the bodies of his daughter and her boyfriend on the first floor. Matthew Wakelin and Powers’ bodies were found on the second floor.

Carbon monoxide is a colorless, odorless and tasteless gas that is slightly less dense than air. It is toxic to humans when encountered in concentrations above 35 parts per million.

Symptoms of mild poisoning can include lightheadedness, confusion, headaches, vertigo, and flulike symptoms.