Chicago – A baby mysteriously kidnapped in 1964 may have finally been found — more than half a century later. Chester and Dora Fronczak's son, Paul, was taken from a Chicago hospital when he was just days old. Shortly after investigators thought they had found him, but decades later, they realized they had the wrong person.

KLAS-TV investigative reporter George Knapp broke the story on MysteryWire.com. Fronczak is now living in Michigan and has kids of his own who heard about his kidnapping, reports CBS News correspondent Adriana Diaz.



"His children became convinced that their dad was the real deal, was the real Paul. They took some tests and tracked it down," Knapp said.



Their father, whose DNA matched the baby's, wants to remain anonymous.



"Imagine what a shock it would be. You're 55 years old. You think you know who you are. You think you know who your family is. And you suddenly get a bolt out of the blue that tells you you're not that guy after all. You're this guy. You're a kidnapped baby," Knapp said.



The mystery surrounding Fronczak began in 1964 when a woman posing as a maternity ward nurse told his mother, Dora, that she needed to take the baby to see the doctor. The woman never came back, sparking a massive search by the FBI.

A year later, law enforcement officials thought they found him when they discovered a boy abandoned in New Jersey with ears shaped like Fronczak's. The Fronczaks adopted him and raised him in Chicago.



In 2013, "CBS This Morning" spoke with the man who grew up believing he was Paul Fronczak.

"My mom and dad pretty much said you're our son. We love you, and that's all you need to know," Paul Fronczak said.

It wasn't until he took a DNA test as an adult that he found out he was not the kidnapped baby.



"I felt the color drain from my face and I started thinking about all these things that everyone takes for granted, like when your birthday, how old you are, who your mom and dad is," he said.



As for this new development, the FBI tells CBS News: "Our investigation into this matter remains ongoing as we continue to pursue all leads… There is no further information at this time."



Knapp said so far, the man believed to the true Paul Fronczak has not reunited with his mother.