A North Dakota woman who mysteriously disappeared last month is now feared to have been ‘heinously murdered’ and dismembered by her boyfriend, cops said.

Isadora Wengel, 25, was last seen at a Walmart in Fargo on January 3, with her family members reporting her missing to Fargo police four days later.

Her disappearance set off massive search efforts across the metropolitan region, with officers at one point working 12-hour shifts for 10 days straight as they searched a landfill, Valley News reports. 

But last week, authorities announced they had arrested Wengel’s boyfriend, 21-year-old Joshua Alexander Hite, in connection with her murder.

‘We do not believe that Isadora is alive,’ Fargo Police Chief David Zibolski said at a news conference. ‘We believe that Isadora was heinously murdered.

‘And we, meaning the police department collectively, have probable cause to believe that Josh Hite, her boyfriend, is the person who murdered and tampered with evidence related to the disposal of her body,’ he continued.

‘We believe this to be a heinous and diabolical crime, and we believe there may be some dismemberment involved,’ Zibolski said as he urged residents between Fargo and Otter Tail County, Minnesota to remain on the lookout for Wengel’s remains.

‘Based on the fact that we know the disposal of her body occurred in extremely cold weather with significant snow on the ground, we now found ourselves in the midst of a mid-winter thaw, which may reveal her whereabouts,’ the police chief said.

Isadora Wengel, 25, is believed to have been ‘heinously murdered’ by her boyfriend

Joshua Alexander Hite, 21, is facing charges of murder, tampering with physical evidence and providing false information, and is being held on a $5 million bail

‘We’re committed to justice for the family and accountability for the perpetrator,’ he added.

Hite and Wengel had been dating since August, and he told authorities she had been staying with him since New Year’s Day, according to court documents obtained by CBS News.

He claimed he and Wengel had an argument on January 4 because he wanted to end their relationship, and said he brought her back to her home the next day.

Hite also allegedly told investigators Wengel left her cellphone in his car, and he went back to her home later that day to return it. He said nobody answered the door and he left the phone on Wengel’s deck.

Investigators described Hite in the court documents as ’emotionless’ and ‘not forthcoming.’

They also detailed how phone data recovered from Wengel’s phone showed some unusual Snapchat activity on January 4, with photos of ceilings and walls inside Hite’s apartment sent to her mother and another contact, according to Valley News.

Family members later told investigators the photos were ‘odd and not common photographs they would receive from Wengel.’

Authorities then searched Hite’s apartment, and investigators seized plastic sheeting, a bathroom mat, bloody gauze and saw blade all containing Wengel’s DNA.

They also recovered a blue latex glove that investigators said contained ‘a mixed DNA profile with majority matching Wengel and a partial sample matching Hite.’

Wengel was last seen at a Walmart in Fargo, North Dakota on January 3 (pictured), with her family members reporting her missing four days later

Fargo Police Chief David Zibolski told the public last week he believes Wengel’s remains may have been dismembered

He urged residents between the Fargo metropolitan area and Otter Tail County, Minnesota to remain on the lookout for HDX 27-gallon tough storage tote, where he believes Hite may have disposed of Wengel’s body

As the investigation continued, officers also allegedly discovered Hite made some suspicious Google searches on January 4 including: ‘home depot Sawzall,’ ‘junk removal near me,’ ‘Dumpster’ and ‘how to register for a legal alias.’

That same day, police said, Hite also ordered a reciprocating saw, plastic sheeting, trash bags and duct tape through DoorDash.

By the time of his arrest, investigators also noticed and photographed recent injuries on Hite’s body – including cuts to his hands, wrists, knees, thighs and bruising on his lower back. 

The 21 year old is now facing charges of murder, tampering with physical evidence and providing false information, and is being held on a $5 million bail.

But Zibolski said his quest for justice is not complete, as the search for Wengel’s remains continues. 

He told the public last week to be on the lookout for an HDX 27-gallon tough storage tote, where he believes Hite may have disposed of Wengel’s body.

‘We know that Mr. Hite had received a specific type of black tote,’ the police chief said. ‘There were actually two of those delivered to his apartment.’

An online fundraiser to help Wengel’s mother, Heather, (pictured with Wengel) and her older sister, Callista, has raised over $14,200

One of the totes was recovered in January, but the other is still missing.

In the meantime an online fundraiser to help Wengel’s mother, Heather, and sister, Callista, has earned over $14,200.

It explains that the two are not working as they try to do ‘everything possible to support the search efforts,’ as they also ‘start the legal process and start thinking about how best to honor [Wengel’s] life and legacy.’

She was described in an online obituary as ‘witty, silly, sarcastic, insightful and incredibly empathetic,’ as well as ‘truly a bright light.’

‘She’s loved and she will continue to be loved,’ her friend MaLeah Jiminez said.