WATERVILLE, Maine (CBS) – For the first time, police have said they believe someone took Ayla Reynolds.

Waterville Police Chief Joseph Massey would not speculate whether the person who abducted her was a member of her family, someone who lived in her father’s house, or a stranger.

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“We believe that someone removed Ayla from the house, and that is where our investigation is focusing,” says Massey. “I don’t want to speculate beyond that, because we do not know who took Ayla out of that house and under what circumstances she was removed.”

WBZ-TV’s Lauren Leamanczyk reports

Police say the search for Ayla continues, but in recent days, tips have dried up.

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At a press conference Monday, police announced a $30,000 reward for information leading to the return of the 20-month-old. Massey says the reward is the result of an initiative by private citizens who want to encourage anyone with knowledge to come forward.

Ayla was last seen on Dec. 17. Her father reported her missing when he awoke to find his daughter’s bed empty.

Since then, police have conducted a massive search of the area around the missing girl’s home and followed up on hundreds of tips they’ve received.

Snow in central Maine hampered a lot of the search efforts this weekend, but police say they will not rest until she is found.

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Just a day before Ayla went missing, her mother Trista Reynolds had filed to get sole custody of the girl. Ayla’s father Justin DiPietro was said to be unaware of that.