Police in Aurora, Illinois, said in an emailed statement that two detectives traveled to the Cincinnati area to assist the FBI in the missing-persons case.
"We cannot confirm that the person of interest here is Timmothy Pitzen," a spokesman with Aurora police said. "At this time we have no further information to provide."
Timmothy's grandmother, Alana Anderson, told NBC News on Wednesday that she has been in touch with Aurora police. Anderson said she never stopped thinking about her grandson.
"His mother left me a letter and she said that he would be with people who would love him and take care of him," Anderson said. "She felt that her life had come to an end and she was going to end her life and she didn't want to leave him without good parenting."
Anderson said she last saw her grandson when he was 6 1/2 years old.
"I just prayed that when he was old enough that he would remember us and contact us," she said. "That was kind of the best I could hope for."
Kara Jacobs, Timmothy's maternal aunt, told NBC Chicago that family members had yet to meet the teen who is recovering in a hospital and that the results of DNA tests confirming his identity are expected to be released Thursday.
The family has heard of multiple false sightings of the missing boy over the years, but this is the most promising development, she said.
"We always felt very strongly that Tim was alive," Jacobs said. "What I've prayed about since he's been gone is that God will keep him close and take care of him. And that maybe, by some stroke of luck, he was with people who would love him."
Jacobs said her nephew knew his home address and grandmother's phone number at the time he disappeared.
Timmothy’s father in Iowa is "trying very hard to hold it together" as he awaits confirmation of the teenager’s identity, Jacobs added.