katie couric. Matt gutman has been following the man who created the hoax. Reporter: In an exclusive interview with katie couric, manti te'o admits he briefly lied to the public after recei receiving... See More
katie couric. Matt gutman has been following the man who created the hoax. Reporter: In an exclusive interview with katie couric, manti te'o admits he briefly lied to the public after recei receiving nows his girlfriend was fake. You stuck to the script. And you knew xhg was amiss, manti. Correct. Why? Put yourself in my situation. Reporter: He's been hound since the story broke. He said up until december, he was not lying. He really was duped and loved a woman he never met. Until he says he got a call from the grave. This girl who I committed MIST TO DIED ON SEPTEMBER 12th. Now I get a phone call on december 6th saying she's alive and I'm going to be on national tv two days later and they asked me same question. What would you do? Reporter: This is the woman he believed he was committed to. Her name is not lennay kekua. It is diana. She says her picture was stolen. I have never met manti te'o my entire life. I have never spoke on the him. Never exchanged words. Reporter: They say they were both unsuspecting victims of this man, roniah tuiasosopo. ♪ Do you ever let to ♪ Reporter: Tuiasosopo seen here in this photograph by tmz is not admitting it publicly. His former football coach describes him as agree grar use. Someone you want as a son? Somebody I want my kids to grow up like. Ronl, disciplined. Reporter: This morning, despite the media frenzy. Hey, guys, can we stop you for one second? He's not talking. More "good morning america," matt gutman, abc news. And all of katie's exclusive
This transcript has been automatically generated and may not be 100% accurate.