The mother of a missing Maine toddler said Monday that she sought full custody of Ayla Reynolds just days before the girl allegedly disappeared from her father’s home.

“My daughter does deserve to be with me,” Trista Reynolds told Nancy Grace in an exclusive interview airing Monday night. “I’m the one who raised her for 18 months.”

Ayla’s father, Justin DiPietro, reported the 20-month-old missing from his Waterville home around 8:50 am on Saturday, telling police that he last saw her when he put her to sleep around 8 pm on Friday night. Reynolds had filed a complaint seeking parental rights on Thursday, but she does not believe that DiPietro was aware of that filing.

Asked why she is seeking custody now, Reynolds called DiPietro “vindictive” and “verbally abusive” and claimed that he has refused to let her have Ayla for even one day since he took custody of her in October. According to her, Ayla has broken her arm and missed several doctors’ appointments since DiPietro started caring for her. He allegedly told her that Ayla was injured accidentally when he fell on top of her while walking up steps with her in his arms.

Attempts to reach DiPietro or his family for comment on Reynolds’ claims Monday were unsuccessful. He has not been charged with any crimes involving Ayla.

Waterville Police Chief Joseph Massey told reporters that investigators are aware of the custody issue and are monitoring it, but he said they still have “every possible thought and angle in mind. This is currently a very open investigation.”

At a Monday press conference, Massey said that the Maine Warden Service was coordinating a search of the Messalonskee Stream near DiPietro’s house. He reiterated that family members have been “very cooperative” with authorities.

Massey refused to address most of the reporters’ questions about specific elements of the investigation, but he said police have not drawn any conclusions about what happened to Ayla from the leads they have pursued so far. He detailed the resources being provided by the several state and federal agencies assisting with the search, saying that all of them have the same goal in mind.

“The focus obviously is to bring Ayla home,” Massey said.

Watch Nancy Grace Monday at 8 p.m. ET on HLN for the latest on the search and Nancy’s exclusive interview with Ayla’s mother.