(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.

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.

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