EXCLUSIVE: What Did They Find? Experts are split as bone-like fragments are unearthed in Gilgo Beach serial killer Rex Heuermann’s backyard – as they say human remains CANNOT be ruled out

Forensic officers have unearthed mysterious items in the backyard of the Gilgo Beach serial killer Rex Heurmann’s home.

Haunting images showed the officers huddled over a hole in the ground while examining what appeared to be small fragments on a plank in the ground.

Some experts speculated the remains could be human, while others warned they could be from animals or something else entirely.

Investigators have been dragging boxes of items from the home for the past two weeks as they rigorously search for evidence linked to the notorious murders.

They’ve uncovered a vast cache of weapons and suspect some of the victims may have been butchered inside the house.

Heuermann, 59, was arrested on July 14 on suspicion of murdering three sex workers whose bodies were found on Gilgo Beach in 2010.

Forensic investigators are seen Monday photographing items found in the Long Island home of Rex Heuermann. Analysts told DailyMail.com the remains could be human but require further investigation

A forensic photographer is seen bending over the tray of items found in Heuermann’s home

Another member of the team stands in the pit dug by the excavator and examines the material found in the ground

Exclusive DailyMail.com photos this week show investigators looking at a tray of what experts say could be human remains.

Heuermann, 59, was arrested July 14 in Manhattan, where he owned an architecture firm. He was charged in connection with three murders at Gilgo Beach

The forensic officers were seen surrounding a digger bucket and examining the items laid out on a white board.

One stood nearby with a large sack into which the items could be lugged after they were photographed.

A doctor and a bones expert analyzed the photos for DailyMail.com and disagreed on the nature of the objects – but said “human remains cannot be ruled out”.

“From a distance, it could actually be people or animals. But it’s too far away to know for sure,” said one doctor.

“DNA tests are urgently needed: we doctors are used to close-ups.”

Another expert, a forensic anthropologist, told DailyMail.com: “In my experience, they look too rectangular to be human.” I wouldn’t immediately recognize any of these objects as human remains.

“But the dark stain on them suggests they’re organic material, and the context in which they were found means I wouldn’t rule out human remains.”

The yellow excavator has been in front of the house on Long Island since Sunday

The items unearthed on Monday were placed in a brown sack and taken away for further analysis

Investigators have spent a lot of time examining Heuermann’s basement, the door of which is apparently left open by his plants

The excavation of the site was carried out by machine and by hand on Monday: you can see men with spades standing at the edge of the pit

The finds are recorded on a tablet after they have been photographed

The site search could be completed by Tuesday

A yellow excavator can be seen outside Massapequa Park on Long Island, home of Rex Heuermann, Monday

Suffolk County Police Commissioner Rodney Harrison told News 12 Long Island investigators could not confirm whether any of the victims ever visited the Heuermann home.

“We’re conducting a full survey around the house to see if there’s anything out there that we need to take a closer look at,” he said Monday.

“Can we confirm that someone was killed in the house?” We cannot confirm that at this time.”

Harrison said the room in Heuermann’s basement was not soundproof, but confirmed that it had extremely thick walls.

Harrison said it may have been used to store his large gun collection.

More than 200 firearms were found at his home in the Long Island suburb of Massapequa Park — though he only had a permit for 92 firearms, prosecutors said.

The first victim, Melissa Barthelemy, 24, was discovered by Suffolk County Police on December 11, 2010. The body of Megan Waterman, 22, was found two days later

Maureen Brainard-Barnes was 25 when she went missing (left). Amber Lynn Costello was 27 years old. Their bodies were found near Barthelemy’s the same day

Heuermann-Ellerup’s Long Island home is pictured Saturday as investigators remove items from the home

Police said they believe the suspected killer murdered at least one of his victims in the home

One of Heuermann’s former colleagues told the New York Post the architect took time off to furnish the concrete-lined space.

“It’s not just a hidden room — it’s a serious vault,” the colleague said.

“It had a huge, sturdy vault door. He went and poured new concrete walls, huge amounts of concrete to encase this space. It was maybe two or three feet thick.’

The police assume that Heuermann’s wife Asa Ellerup (59) and their children were not involved in the murders.

Analysis of phone records shows that Ellerup was out of town in 2009 and 2010 when Melissa Barthelemy, Megan Waterman and Amber Costello went missing.

She was in Iceland, where she was born, visiting friends in New Jersey.

Heuermann is also a suspect in the 2007 death of Maureen Brainard-Barnes, however telephone records from the period are no longer accessible.

Harrison said Heuermann’s family were stunned to learn of his alleged crimes.

“They were disgusted. “They were embarrassed,” he said. “So if you ask me, I don’t think they knew about this double life that Heuermann led.”

Ellerup filed for divorce last week and has not returned to the home, which remains on lockdown.

Harrison said the search of the home could be completed as early as Tuesday.

“I want to think we’ll be ready tomorrow or later this week,” he said.