(CNN)Margaret Ellen Fox was a 14-year-old reportedly on her way to what she thought was a babysitting job when she disappeared in June 1974.
Do you recognize the voice of a man connected with a possible 1974 kidnapping? The FBI wants to know
While authorities listened in to phone calls coming into her New Jersey home after she went missing, a man told her parents he had Margaret.
According to an audio file posted on the FBI news release about the cold case -- a clip enhanced with new technology -- the man said, "$10,000 might be a lot of bread, but your daughter's life is the buttered topping."
That was 45 years ago this week. Margaret has never been found.
In addition to releasing the six-second audio clip, the FBI released images of what Margaret might look like now and announced a $25,000 reward.
"Margaret Fox was loved dearly by her family and friends," Burlington County Prosecutor Scott Coffina said. "To this day, her disappearance continues to cause great sorrow. If someone out there possesses information that could assist the investigators working to solve this mystery, I urge you to come forward."
She disappeared June 24, 1974, after she got on a morning bus traveling from Burlington to Mount Holly. That's about 7 miles. Witnesses told investigators they saw a girl matching Margaret's description get off the bus.
Police aren't sure whether the voice on the audio recording is the same person who answered Margaret's newspaper ad and purportedly wanted to hire her to babysit his son, authorities said.
The phone used to hired Margaret was at a supermarket phone booth in Lumberton, the FBI said.
"The disappearance of Margaret Fox has haunted this community for decades," Burlington Chief of Police John Fine said. "I want to bring closure to this case and bring home an answer to the Fox family and community."