IGNACIO, Colo. Nov. 26, 2012 -- The mother of 13-year-old boy Dylan Redwine, who disappeared a week ago during a court ordered visit to his father, fears that the dad may have done something to "remove Dylan from the situation."
Dylan Redwine was last seen at the home of his father, Mark Redwine, when he vanished seven days ago.
"I was married to Mark for a lot of years, and I know the way he reacts to things," Elaine Redwine told ABC News. "If Dylan maybe did or said something that wasn't what Mark wanted to hear, I'm just afraid of how Mark would have reacted."
Elaine and Mark were divorced and live about five hours away from each other, ABC News affiliate KMGH reports. Dylan was staying at his father's home because of a court order granting his father visitation rights for Thanksgiving.
Elaine Redwine told ABC News she believes her ex-husband was upset that she was the court-mandated primary custodian of their son.
"I don't think Mark treats him very well," Elaine Redwine said. "I would not put it past Mark to have done something to remove Dylan from the situation. You know, like 'if I can't have him, nobody will.'"
Dylan had been with his dad in Vallecito, Colo., for just one day before he went missing. Mark Redwine told police that his son was in his home when he left to run some errands at 7:30 a.m. When he returned four hours later, the boy was missing.
Elaine Redwine told ABC News she was having a difficult time getting in touch with her ex-husband about their son.
"He hasn't had any contact with us. [My older son] tried to get a hold of him by texting him, and he wouldn't respond," she said. "I just find it odd that at a time like this, he would be so evasive."
Mark Redwine declined to speak to ABC News.
Police say they are considering a number of possibilities, including abduction and the possibility that Dylan ran away.
"Foul play is definitely something we are looking at, but we're hoping it's a runaway case and that Dylan will show up and will be fine," La Plata Sheriff's Office spokesman Dan Bender said. "Because we don't have any clues that point in any particular direction, we have to consider every possibility."
Dylan's mother and older brother both insist Dylan wouldn't run away without contacting them, or if he did run away from his dad's home, he would have gone to them.
"When he was afraid in any situation, he knew he could call me and I would drop everything and go out there, first thing," Dylan's brother, Cory Redwine, 21, told ABC News. "He knew that me, my mom, my step-dad, any of us, if he called us and said, 'I need your help,' he knew we'd be there."
Hundreds of people have turned up to help search for Dylan, but so far police say they are no closer to finding him.
"We had people in the air, on horseback, on ATVs, search dogs, and we got no clues from any of that," Bender said.
Dive teams are searching nearby Vallecito Lake using a high-powered sonar gun, after searches this weekend revealed nothing, according to KMGH. Search teams are also combing the shoreline around the lake.
Elaine Redwine told ABC News she thinks somebody must know something, and she hopes they come forward.
"Vallecito is a small community. If anybody has seen anything or knows anything, no matter how big or small it seems, please tell us," Redwine said. "Everything right now is crucial to bringing my little boy home."
Redwine is described as 5 feet tall, 105 pounds, blond hair, blue eyes and fair complexion. He was last seen wearing a black Nike shirt, black basketball nylon shorts, black Jordan tennis shoes and a two-tone blue and white Duke Blue Devils baseball hat.