But in another extraordinary twist in the scandal that has engulfed the Notre Dame linebacker, it has emerged that Te'o was in fact speaking to a man who disguised his voice during the more than 500 hours of phone calls the pair shared.

In Te'o's first television interview since it was revealed last week that Kekua did not exist, the 21-year-old claimed one of his acquaintances, Ronaiah Tuiasosopo, had disguised his voice and assumed the identity of Kekua to try to establish a romantic relationship with him.

Te'o claims Tuiasosopo, using the fake name and fake photographs, approached him on social media and they soon became a couple, communicating online and on the phone despite never meeting.

And Te'o said he completely fell for the ruse.

"It didn't sound like a man," Te'o told ABC presenter Katie Couric during the interview that aired on Thursday in the US.

"It sounded like a woman. It's incredible that he can make that noise."

He also supplied several voicemail messages that were left by Kekua on his phone, and that were played during the interview. Tuiasosopo, 22, has had dramatic training and last year auditioned for the television show The Voice.

Te'o was a runner-up for the Heisman Trophy, the award for the best college football player in the US, and the story of his girlfriend's death from cancer in September last year became an essential part of his personal narrative, featuring on the front page of Sports Illustrated and countless newspapers across the country.

Te'o admitted that he had misled reporters, the public, and his own family about the nature of his relationship with Kekua because he hadn't wanted to be seen as a "weirdo" for not having met her in person.

But he maintained he played not part in staging the existence of Kekua for publicity.

Couric said there was speculation that Te'o had continued with the fake relationship to cover up his sexual orientation, and asked him: "Are you gay?"

"No," Te'o, laughing. "Far from it. Far from it."

Te'o says the first time he found out something was amiss was on December 6, when he received a phone call from Kekua, three months after she supposedly died from cancer.

But he told Couric that he was not certain that her existence was a hoax until January 16, when Tuiasosopo had called to confess that he was responsible.

"He didn't say why, he just explained he wanted to help people," Te'o said.

"It was his way of helping people."

Asked what he would say to Tuiasosopo if he had the chance, Te'o said: "You hurt me."

smh.com.au