Kansas City, Mo., police issued an Amber Alert for Lisa Irwin, an infant who disappeared from her Kansas City home overnight on Oct. 3.

Kansas City, Mo. ? The parents of a missing 10-month-old Missouri girl are no longer cooperating with investigators, police said late Thursday — an assertion the family quickly and firmly denied.

At an evening news conference, Kansas City police spokesman Steve Young said Jeremy Irwin and Deborah Bradley stopped cooperating with authorities Thursday. The couple had been working with police since the disappearance of their daughter, Lisa, who the parents say was snatched from her crib sometime late Monday or early Tuesday.

“Tonight, they decided to stop talking to detectives, and I don’t have to illustrate how that affects the investigation. That speaks for itself,” Young said.

Relatives of the couple later called their own news conference, where a sister of Irwin read a statement saying “we have never stopped cooperating with police.”

“We’ve been cooperative from day one, and we continue to assist the police with the investigation,” the statement.

Young also said the parents’ claim that whoever took their daughter also stole their cellphones hadn’t produced any leads. And he reiterated that investigators still have no suspects.

Asked after the news conference what would happen to the investigation without the parents’ cooperation, Young said he could not comment.

The sister said the parents would make a statement sometime today; she did not take any questions Thursday night. A call to police for reaction to the family’s statement was not immediately returned.

During a tearful news conference Thursday morning, Irwin and Bradley had described how they frantically searched their home for any sign of their daughter after her father came home from work early Tuesday and she wasn’t in her crib. They said they found an open window, an unlocked front door and house lights blazing, and later discovered that their three cellphones were gone.

“They told us three cellphones were missing. It hasn’t produced anything we can go forward with,” Young said. “The investigation is directed and handled by hard information.”

Investigators focused their search Thursday on a heavily wooded area, sewers and an industrial park. About 100 officers were scouring the industrial area and adjacent woods, while others were lifting drain covers and crawling inside.

But after the evening news conference, police spokesman Darin Snapp sent out a news release saying authorities believed they had done everything they could “regarding geographic searches” and were shutting down the command post about a mile from the home. Snapp said police “will continue tracking leads as we get them or develop additional information.”

Earlier in the day, a cousin of the baby’s mother said Lisa’s parents have given police more than a dozen names as they try to think of potential suspects or people who paid especially close attention to the child.

“We’re scraping for anything, anyone who was at the house, who looked at her strange. Anything,” said Mike Lerette.

Irwin said he immediately knew something was wrong when he returned home from work about 4 a.m. Tuesday. He checked on their other children, 6-year-old and 8-year-old boys, then went to Lisa’s room and discovered her gone.

“I said, ‘What do you mean she is not in her crib?'” said Bradley, who had checked on her daughter about five hours earlier. “I just knew, you know, that something was really wrong. We ran around the house and screaming for her, but she was nowhere.”

Bradley said that’s when they discovered the phones had been taken, guessing it was to delay them from calling police. As she hugged her crying sons, Bradley said, Irwin checked outside and eventually contacted police.

“All I can think of is that maybe somebody wanted a baby,” she said.

Lisa has blue eyes and blonde hair, is 30 inches tall and weighs around 28 pounds. She was last seen wearing purple shorts and a purple shirt with pictures of white kittens.

Authorities have used search dogs to go over the family’s home and nearby woods, helicopters, all-terrain vehicles and door-to-door interviews with neighbors.