The nurse that has become a person of interest in the case of the missing Colorado mom Kelsey Berreth is thought to have been in a romantic relationship with Patrick Frazee for months, the Daily Mail reports. Frazee was the fiancé of Berreth, the father of her daughter, and believed to be the last person to see her alive.

Two individuals that professionally know the 32-year-old Idaho nurse told the Daily Mail about the alleged romantic relationship between the two. They claim that Frazee was having an affair with the woman, who divorced her husband a few years ago.

The nurse and Frazee reportedly had met a rodeo and may have begun their relationship as early as 2016, before Kaylee, Frazee’s and Berreth’s daughter, was born, according to the Daily Mail's sources. They also said the nurse was in Colorado around Thanksgiving. Berreth was last seen at a Safeway grocery store in Woodland Park, Colorado, on Thanksgiving Day.

The nurse is believed to have been the one to dispose of Berreth’s phone in Idaho, where it pinged off a cell phone tower three days after she went missing, ABC News reported. The name of the nurse has not been revealed, and she has not been charged with a crime.

Frazee was in court on Thursday for a custody hearing where a judge ruled that Kaylee would remain with Berreth’s parents as a temporary custody arrangement. The Berreths attended the hearing via phone, the Daily Mail reported.

Frazee has been formally charged with murder, but no other arrests have been made at this time. According to the court complaint, Frazee plotted the murder of Berreth with at least one other person three months before she disappeared.

Berreth’s remains or body has not been found at this time. Prosecutors said Monday that there was enough evidence to suggest the two ways that Berreth was killed by Frazee.

Frazee is scheduled back in court on Friday for an anticipated four-hour hearing regarding his upcoming trial.