Karl Rominger, one of Jerry Sandusky's defense attorneys, confirmed for ABC News the existence of the audio tape.
"As a general rule it's a tape of Matt (Sandusky) making the allegations. I don't feel comfortable going into specifics about what he says, but I'll say that he is an alleged victim, so that will tell you some," said Rominger, who has listened to the audio recording of the interview.
The recording shows Matt Sandusky, whom Jerry and Dottie Sandusky adopted in his teenage years, hesitating to talk about the abuse allegations because he had previously said under oath that his father had not molested him, Rominger said.
"The problem is," Rominger said, quoting Matt Sandusky from the audio tape, "'I don't want to get into trouble for perjury'... because he previously said other things."
He then goes on, however, to detail allegations which Rominger said echo those of other alleged victims, specifically those represented by Matt Sandusky's attorney, Andrew Shubin. Shubin represents the men known as Victim 3 and Victim 7 in court documents.
"It seems like that story magically tracks one of Shubin's clients' stories," Rominger said. "A lot of these kids seem to have this kind of magnetic memory that comes back over time. (Matt's) comes back all of a sudden."
A source close to the state's investigation confirmed the existence of the audio recording to ABC.
Matt Sandusky came to prosecutors during the first week of the trial to say that he, too, had been molested by his father. Prior to that, Matt had been a staunch supporter of the former Penn State football coach, who took him in when he was a teenager and later adopted him. Matt was listed as a witness for the defense at the beginning of the trial.
After meeting with him on Thursday, prosecutors notified the defense that Matt Sandusky could be called as a rebuttal witness before the trial's completion. Defense attorneys cited that fact as the reason for not putting Jerry Sandusky on the stand to defend himself, lest the prosecutors then call Matt Sandusky to talk about his own alleged abuse.
Matt Sandusky has so far declined to go public with his allegations, though Shubin released a statement saying that Matt was a victim of his father.
Sandusky was found guilty on 45 counts of child sex abuse on Friday night following a two-week trial that saw eight men testify against him about being molested. One man, known as Victim 4, said that when Sandusky began a soap fight with the boy in a Penn State locker room shower one day, Matt Sandusky left quickly and acted "nervous."
Matt Sandusky watched only the first day of the trial before he was sequestered as a possible witness for the defense.Sandusky's attorneys began discussing a possible appeal of the guilty verdicts just moments after leaving the courthouse Friday.
Sandusky's lead lawyer Joseph Amendola told ABCNews.com today that it was "not definite" that he would stay on to handle the appeal, but said, "I anticipate I'll be a witness for Jerry on his appeal."
Rominger confirmed that he planned to stay on for the appeal process.
But both men began looking ahead to an appeal almost as soon as Sandusky was convicted on 45 of 48 counts of child sex abuse. Sandusky's bail was revoked and he now sits in Centre County Correctional Facility until his sentencing, in approximately 90 days. Sandusky, 68, faces more than to 450 years in prison.
"We had volumes of materials that we really didn't have sufficient time to review prior to start of this trial," Amendola told ABC News Friday night following Sandusky's conviction.
"Until we go through those materials and talk to one of our experts who was unable to testify in this case within the time constraints, we really wont' know what issues are involved in those particular matters," Amendola said.
Amendola and Rominger both said that they would be able to file appeals on issues including the lack of preparation time ahead of trial and the improperly-edited audio recording of an interview Sandusky gave to NBC's Bob Costas.
Sandusky's lawyers had requested multiple continuances from Judge John Cleland ahead of the trial, claiming that they did not have enough time to adequately prepare a defense. Days before the trial started, they submitted a sealed petition asking to withdraw as Sandusky's legal counsel on those grounds, but Cleland denied the petition, Rominger said on his weekly radio show.
"There are appellate issues," Rominger told ABC News.
Pennsylvania Attorney General Linda Kelley said that an appeal would likely not be successful.
"The defense in this was given a lot of discovery material, they were made aware of all the charges in the case, and what the commonwealth intended to present. We don't believe it was rushed into court," she told ABC News Friday.
Attorneys may also appeal Sandusky's verdict based on the NBC audio recording prosecutors played for the jury. Last week, Amendola asked Cleland to declare a mistrial after the recording played in court made it sound like Sandusky was stalling or hesitating when asked, "Are you sexually attracted to young boys?"
During the actual interview, Sandusky responded, "Am I sexually attracted to young boys? Well, I enjoy young people," and went on to say he was not sexually attracted to them. But the recording played for the jury at the trial made it sound like Costas had to repeat his question and that Sandusky was reluctant to answer it.
According to sources close to the case, Cleland was angry about the mess up and considered Amendola's request on the grounds of prosecutorial misconduct. To avoid a mistrial, the attorney general's office then reached out to NBC, asking them to send all of their versions of the interview to the judge.
NBC News spokeswoman Amy Lynn confirmed this weekend that NBC supplied three different versions of Costas' interview with Sandusky to prosecutors, and that one of the versions contained the error.
"Prosecutors used the 'Today' version, not realizing it included a technical glitch, and played it for the jury," Lynn said in a statement Sunday.
"After court that day, NBC News executives had a series of discussions with the prosecutors, and after some internal investigation were able to determine that the glitch originated on 'Today,'" she said.