Police have arrested the husband of the Idaho mother charged in the disappearance of her two children who haven’t been seen since September.

Chad Daybell was taken into custody for questioning Tuesday, the same day that human remains were discovered on the man’s property in Salem, Idaho, according to several news reports.

Rexburg Police Sgt. Gary Hagen later confirmed human remains were found at Daybell's home Tuesday in Fremont County, according to East Idaho News, which has closely followed the case from the outset.

Police later clarified that Daybell had not been officially charged with a crime, the outlet reported, although photos showed him being led away in handcuffs on the side of a road, where he was pulled over and arrested.

The remains have not been identified.

Several backhoes were seen entering the property.

The major development in the case was first reported by Fox 10 News in Phoenix.

Daybell had been under investigation in the death of his previous wife, Tammy, who went to sleep Oct. 19 and never woke up. Two weeks later, Daybell eloped to Hawaii and married Lori Vallow, who was then arrested in February on felony child abandonment charges. She was extradited back to Rexburg, Idaho, in March, where she has remained jailed on a $1 million bond.

Her children have not been seen since September.

The ongoing saga has many twists, including several suspicious deaths and family accusations that Daybell and Vallow are members of a Doomsday cult.

Vallow maintains her innocence, although she has not cooperated with the investigation nor provided authorities any hints to the whereabouts of 7-year-old Joshua “JJ” Vallow and 17-year-old Tylee Ryan.

Authorities pulled over Daybell’s silver SUV late Tuesday morning about a mile south of his Rexburg home in the 4000 block of 1900 East, according to reports.

Earlier, FBI agents and Rexburg police arrived at Daybell’s front door at 7 a.m. armed with a federal search warrant. Reports did not reveal if Daybell was home at the time.

The bureau’s Evidence Response Team was on the scene along with law enforcement officials from Madison County.

Police collected 43 items in a previous raid at the house Jan. 3, East Idaho News reported.

Daybell and Vallow were being investigated by the Idaho Attorney General’s Office for conspiracy, attempted murder and murder in connection to Tammy Daybell’s death.

Her body was exhumed from the Springville Evergreen Cemetery in Utah in December, and officials were awaiting the results of toxicology tests.

Neither Chad Daybell, 51, nor Vallow, 46, had been formally charged, although prosecutors are considering possible conspiracy, attempted murder and murder counts, according to East Idaho News.

Raising suspicions, Amazon shopping records unearthed in March show a wedding ring was purchased a little more than two weeks before Tammy died, and that Chad Daybell also shopped online for wedding dresses the day after her passing.

Under a cloud of suspicion, Vallow vanished from Idaho in November just as authorities were preparing to carry out a welfare check. She resurfaced a month later in Hawaii.

There were no signs the children were ever with her.

Then in December, two months after Tammy Daybell’s death, Lori’s brother Alex Cox also died of unknown causes, according to reports. Cox, who appeared with Vallow and the children in Sept. 8 family photos at Yellowstone National Park, claimed self-defense in the July 2019 shooting death of Lori’s fourth husband, Charles Vallow, who was Joshua’s adoptive father.

Tylee and Joshua were at home when Charles Vallow was shot to death. Reports said Lori Vallow threw a pool party at the house on the same night.

Cox was never arrested or charged in Charles Vallow’s death, but Arizona authorities are continuing to investigate.

— This is a developing story. Check back with AJC.com for the latest details.