FURTHER chilling details have been revealed about a young victim of one of America’s most horrifying unsolved murders.

Cops called to the site of a blazing fishing boat near a small Alaskan village four decades ago were greeted by a truly gruesome site.

One day in September 1982, the remains of seven people were discovered on the burning wreckage of The Investor close to the fishing village of Craig, Alaska, some 60 miles west of the city of Ketchikan.

Among the victims were Mark Coulthurst and his pregnant wife Irene, both 28, their daughter Kimberly, five, and four deckhands.

The case remains unsolved 40 years on, making it Alaska’s worst unsolved mass homicide.

But among the horror details of the case, was one even more disturbing.

Leland Hale is the an author of several books on the so-called ‘Investor Murders,’ and has studied the case for decades.

Speaking to The U.S. Sun, he revealed that the fire was so fierce that the body of Mark and Irene’s youngest child, four-year-old John, was never identified.

“They were able to identify six of the eight on board right away,” he said. “It took considerable time to identify the other two.

“That’s because the ship was torched with gasoline and it was a fiberglass vessel, so it burned really, really hot, and it burned for a very long time.”

“There were no fireboats in Craig, so there were some, shall we say, amateurish efforts to put out the fire that also compromised the scene.

“And so they’re going through every single piece of the vessel. They’re on shore, they can’t bring it in, they’re afraid it will sink because the vessel’s compromised.

“So they’re going through it, they’re improvising, they’re using shrimp screens to go through and find bones and they do find bones, but of course, as time goes on, the bones are finding are smaller and smaller because it burns really hot.

“It burns so hot that the four-year-old child who was on board the boat, they never found his body. Any sign of him.

“He was never found. So it’s the worst possible scene.”

Read Related Also: I Thought Pulling Fire Alarm Would ‘Open the Door’

The ship had arrived at the tiny fishing village of Craig, home to just 500 permanent residents, on September 5, just before the end of the salmon season.

It was Mark’s birthday, and the crew were celebrating in a local bar as they marked what had been a successful summer of fishing.

They headed back to their boat at around 9.30pm that night.

When cops discovered the bodies, Leland said, “everything changed.”

He explained: “This is not somebody burning their boat to get insurance money. There’s a body here… There’s been a murder here.”

The case left investigators baffled because there was no obvious motive for the horrific crimes.

Mark was a successful fisherman from Blaine, Washington, just under 100 miles north of Seattle on the Canadian border.

Leland explained how Mark had built up his business from scratch, getting a loan approved to buy his state-of-the-art new boat The Investor, an almost unheard-of move in the fishing community.

One of Coulthurst’s former deckhands, John Peel, was later charged with the crimes in 1984.

Authorities later claimed how the suspect – described as a white male with a pockmarked complexion in his early 20s – had been seen the day before the bodies were found.

Eyewitnesses described the suspect steering the vessel – with presumably the bodies inside – to a secluded bay just outside of town.

He was then seen returning to town to pick up a can of gasoline and heading back to the ship just hours before the blaze.

The suspect was never seen again, and cops instead were left to pick up the pieces of the sickening crime.

But after he was found innocent in two successive murder trials, cops said that the case is officially closed.