Missing Harmony Montgomery’s father Adam allegedly punched the partially blind girl in the face, made her clean a toilet with her toothbrush and stand in the corner for hours, according to New Hampshire court documents -- and then failed to provide confirmation of her whereabouts or well-being from family members and authorities for more than two years.

Harmony was reported missing last week, but police then discovered her whereabouts have been unknown stretching back to the fall of 2019. 

Adam Montgomery, an alleged substance abuser with criminal records in New Hampshire and Massachusetts, assumed custody of his daughter in early 2019, according to New Hampshire court documents released Wednesday, after his arrest on assault and child endangerment charges in connection with Harmony’s disappearance.

New Hampshire authorities have arrested the father of missing 7-year-old Harmony Montgomery in connection with a 2019 assault against the child. (Manchester Police)

MISSING HARMONY MONTGOMERY'S FATHER ARRESTED IN NEW HAMPSHIRE

He is allegedly estranged from his current wife since late last year after relapsing and moving into a sober house, then running off with a woman who claimed they have been romantically involved for at least a year, according to court documents released Wednesday.

They state that Crystal Sorey, Harmony’s noncustodial biological mother, told Manchester police on Nov. 18, 2021, that she believed her daughter was missing and that she couldn’t get in touch with her father.

Manchester police visited multiple addresses linked to Montgomery but could not find him for weeks. Harmony’s whereabouts remain unknown and investigators in multiple states have kicked off a large-scale search effort.

On Dec. 27, New Hampshire’s Division for Children, Youth and Families also told Manchester police they couldn’t find the girl. As investigators dug into the case, they said they discovered that Harmony "had not been physically seen since October/November 2019."

Sorey lost custody of Harmony in 2018, according to the documents, and she told investigators that both she and Montgomery had prior substance abuse issues.

The last time she saw her daughter was during a FaceTime call around Easter in 2019, according to investigators. 

"[Harmony] seemed frightened," according to a police affidavit, and Montgomery was visible in the background.

Court documents reveal Sorey regained sobriety by 2021 and tried to locate Montgomery and Harmony. During that time, the adoptive parents of Harmony’s biological brother Jamison told Fox News Digital they were also trying to reunite the siblings and were in contact with Sorey.

MISSING HARMONY MONTGOMERY: ADOPTIVE PARENTS' PUSH TO REUNITE SEPARATED SIBLINGS TRIGGERED SUSPICIONS

Police continued to search for Harmony and Montgomery last week and made contact with her uncle, Michael Montgomery, who told them "he had concerns that Adam was physically abusive towards [her]," according to the affidavit.

Adam Montgomery’s uncle, Kevin Montgomery, reiterated those concerns and said around the time of the alleged 2019 assault he saw Harmony with a black eye. He told police that his nephew told him "I bashed her around the house" as punishment after her little brother started crying.

"Adam explained that he had left [Harmony], who would have been 5 years old at the time, in charge of watching her infant brother while Adam was in the bathroom," the affidavit states, citing Kevin Montgomery’s version of events. "Allegedly the younger brother started crying during that time. Adam [allegedly] told Kevin that he returned and found [Harmony] holding her hand over the child’s mouth to stop him from crying."

Then, he allegedly punched her in the face.

NEW HAMPSHIRE POLICE ANNOUNCE 24/7 DETECTIVE-MANNED TIP LINE FOR MISSING 7-YEAR-OLD HARMONY MONTGOMERY

Harmony is about four feet tall and 50 pounds. She has blonde hair and blue eyes and should be wearing glasses. She’s also blind in her right eye.  

Court documents do not identify which eye he allegedly struck.

"Kevin said he believed that Adam had relapsed on drugs during that timeframe," the affidavit continues.  Montgomery was allegedly an abusive disciplinarian known for hard spankings, forcing Harmony to stand in the corner for hours and forcing her to scrub a toilet with her toothbrush.

Montgomery and his current wife, Kayla Montgomery, have three younger children who are all accounted for, according to authorities. She confirmed that she had seen Harmony once with a black eye but said her husband blamed it on one of the other children.

She said she hasn’t seen her husband in months because he moved into a sober house and then to Maine. She also told detectives that she hadn’t seen Harmony since November or December in 2019, according to the affidavit.

Manchester police arrested Adam Montgomery Tuesday on charges he assaulted his partially blind daughter Harmony when she was 5 years old in 2019, leaving her with a black eye. (Manchester Police)

The last time she saw her, she told investigators, was when Adam Montgomery allegedly told her he was driving Harmony to Sorey, who at the time lived in Lowell, Massachusetts. 

"Kayla claimed she never saw, or heard about [Harmony] after that day," according to the affidavit.

Police tracked Adam Montgomery to a vehicle in Manchester, where he was asleep with a new girlfriend on Dec. 31, according to the affidavit.

The woman told police she knew Montgomery had three children with one woman and a fourth with another, but said he never spoke about Harmony to her in the year they were romantically involved, according to the affidavit.

When police questioned Montgomery, they allege that he gave them contradictory statements – including first claiming to have recently spoken to Harmony and then backtracking to say the last time was when he claimed Sorey picked her up around Thanksgiving 2019.

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Then he allegedly stopped answering questions and told investigators, "I have nothing else to say….If I’m not under arrest, I’m leaving."

They arrested him Tuesday, according to a joint statement from local and state prosecutors and Manchester police.

Ahead of his expected arraignment Wednesday, Montgomery waived his right to a bail hearing and agreed to be placed in preventive detention.

The court also issued no-contact orders preventing him from reaching out to Montgomery's mother and his estranged wife.

The search for Harmony is ongoing. Anyone with information is asked to call the dedicated tip line at 603-203-6060.