WATERVILLE, Maine — An underwater search of the Kennebec River turned up no sign of missing toddler Ayla Reynolds on Wednesday, but authorities said that won’t damper their diligence in following up on leads and tips that continue to pour in.

Dive teams from the Maine State Police and Maine Warden Service battled frigid temperatures as a total of 18 divers scoured the river bottom between Hathaway Creative Center, a former mill complex near Waterville’s downtown, and Donald Carter Bridge. Divers also searched a portion of Messalonskee Stream on Wednesday, according to Maine Public Safety spokesman Stephen McCausland.

Maine Warden Service Lt. Kevin Adam said Wednesday’s search was part of a process of elimination of places where 20-month-old Reynolds might be, and that the areas searched Wednesday were chosen because they are “common points of access” to the river. Those include locations, such as a boat launch south of downtown Waterville, that are easily accessible. Adam said no specific tip led authorities to that area and that similar searches will be conducted until Ayla is found.

“There have been tips for bodies of water all over this place,” said Adam to a throng of reporters Wednesday afternoon. “We’re not going to stop until this case has some finality.”

McCausland said though the investigation continues on a daily basis, he did not expect any more intense searches like Wednesday’s this week.

Wednesday marked the 26th day since Ayla’s father, Justin DiPietro, told police the child had disappeared from her bed overnight. Police have not publicly identified any suspects in the case, but McCausland said Wednesday they also have not ruled out any person or any scenario. On Dec. 30, Waterville Police Chief Joseph Massey said the case had gone from a missing person case to a criminal investigation.

McCausland said Wednesday investigators have intended to search the area between the Hathaway Creative Center and the Donald Carter Bridge for a couple of days.

“Those areas needed to be eliminated in the search for Ayla,” said McCausland. “If nothing is found, we’ll move on to other areas.”

Wednesday’s underwater searches, which involved several divers, two airboats and numerous Maine State Police and Maine Marine Patrol personnel, marked the first time divers have been used in an attempt to locate 20-month-old Reynolds. Police have said repeatedly that DiPietro and Ayla’s mother, Trista Reynolds, have cooperated fully with investigators.

The area being searched Wednesday covered about a half-mile of the river and was located downstream from some waterfalls and a dam complex. Adam said air temperatures in the teens and water temperatures near freezing caused difficulties with equipment and was hard on the divers.

“They’re wearing dry suits … but it’s still hard on your body,” he said.

McCausland said the number of tips received by investigators has ballooned to more than 600 to date and have come from throughout Maine and across the country. He attributed the volume of leads to intense attention to the case from local and national media and a $30,000 reward offered Dec. 26 by a group of Waterville-area businessmen. He said investigators welcome all the attention and on Tuesday urged members of Ayla’s family to continue to talk with reporters.

“We encouraged them to talk with the media to keep the story of Ayla in the headlines,” said McCausland, who also encouraged members of the public to come forward with any information at all, no matter how trivial it might seem.

“That might be the piece of information that could crack this case wide open,” he said. McCausland deflected several questions from reporters about who was in the DiPietro home when Ayla disappeared and the timeline leading up to that night, citing the ongoing investigation.

“We’re not going to get into investigative details,” he said. He urged anyone with possible information about the case to call the Maine State Police’s Augusta barracks at 207-624-7076.

Someone inside the DiPietro home on Violette Avenue in Waterville did not answer the door early Wednesday afternoon. Dozens of teddy bears and dolls were sitting out front, testament to the emotional chord Ayla’s disappearance has struck with the public.

Waterville Chief Massey said the pressure on his department — which at this point is playing a support rule in the investigation being led by Maine State Police — has been intense, but he thanked the Greater Waterville community for its support.

“Our intensity and commitment to finding Ayla is the same as it was on Day One,” he said. “We will continue to provide every resource the Waterville Police Department has to this investigation.”

Watch bangordailynews.com for updates.

Christopher Cousins

Christopher Cousins has worked as a journalist in Maine for more than 15 years and covered state government for numerous media organizations before joining the Bangor Daily News in 2009.