ST. CLOUD, Fla. — The estranged husband of missing Osceola woman Nicole Montalvo has been named a person of interest in her disappearance, according to the Osceola County Sheriff's Offce.

• Possible human remains found on 5-acre property in St. Cloud
• Her estranged husband, his father arrested on unrelated charges
• Sheriff's Office says they're also being considered persons of interent in Nicole Montalvo's disappearance
• RELATED: Osceola Deputies Searching for Missing Mom Nicole Montalvo

Christopher Otero-Rivera was arrested on an unrelated probation violation, and is expected to have a first appearance in court today.

Otero-Rivera's father, Angel Rivera, was also arrested on unrelated charges, and is also considered a person of interest.

Possible human remains were found Friday in a search on a St. Cloud property for clues into the missing-persons case of Montalvo, who was last seen there Monday dropping off her 8-year-old son.

Osceola County Sheriff Russ Gibson said investigators "uncovered the possible remains of a human being" on the 5-acre property, where they began digging Thursday evening.

He said the remains were found in the back of the property on Hixon Avenue in St. Cloud.

The Medical Examiner's Office also was called to the scene.

The search continues Saturday morning. K-9 teams were brought out to the area. Deputies say the search will take some time.

“We need to continue searching," said Major Jacob Ruiz with Osceola County Sheriff's Office. "It's a 5-acre lot, it's a big property with a lot of different buildings and vehicles, some wooded area, lake, so it's an extensive search that's gonna take some time.”

Investigators said Montalvo had stopped by Monday night to drop off her son with his father and grandparents, who live there. She hadn't been seen since. Her cell phone was turned off, and her 1999 Honda was found abandoned on Big Sky Boulevard, deputies say.

Deputies also said Otero-Rivera has also had domestic violence issues with Montalvo in the past.

According to an Osceola County Sheriff's Office affidavit dated October 4, 2018, Otero-Rivera and a woman were accused of attacking Montalvo.

Multiple felony charges were filed, but according to court documents, the state declined to prosecute the more serious charges of kidnapping with intent to inflict bodily harm and robbery during a plea deal. The judge withheld adjudication on Otero-Rivera for the charges of tampering with a witness to hinder communication to law enforcement, unlawful possession of a stolen debit card, and battery.

“Our detectives will be in contact and interviewing anybody that we believe has any connection with the disappearance of Nicole, what we are finding here at the scene, and anything involving that, and we can't lose sight that this is missing person investigation,” said Major Jacob Ruiz with the Osceola County Sheriff’s Office.

Anyone with information on Montalvo is urged to call the Osceola County Sheriff's Office at 407-348-2222.