Less than three months after Madeline Kingsbury went missing in southeastern Minnesota, police said they have arrested the father of her children in connection with her disappearance.

Adam Fravel, 29, was arrested Wednesday "on probable cause" after a law enforcement officer found human remains "using information generated during the Madeline Kingsbury investigation," the Winona Police Department said.

Police did not announce charges against Fravel but records from the Winona County Detention Center show he was being detained Wednesday on a second-degree murder charge.

The remains were found Wednesday afternoon in some brush off of Highway 43 in neighboring Fillmore County, police said. Investigators are working with several state and local agencies to identify the remains, police added.

Kingsbury, 26, was last seen on March 31. That day, she did not show up to work or answer calls from family and friends, police have said. The mother also did not show up to pick her children up from daycare that afternoon, they said.

In April, police said that evidence suggests Kingsbury's disappearance was "involuntary and suspicious" and investigators "remain extremely concerned for her safety."

Fravel has denied any involvement in Kingsbury's disappearance.

The Winona County Health and Human Services Department took custody of Kingsbury's children after she went missing, according to court documents obtained by CNN. A judge ruled in April that the children would remain in county custody rather than be released to their father.

Fravel did not have custodial rights to the children, ages 5 and 2, before Kingsbury disappeared, court documents show.

Police are expected to provide more details on the case during a news conference Thursday.