Te'o, 21, gave an exclusive interview to ABC's Couric about the story that surfaced last month, saying he had been tricked into believing his online girlfriend, Lennay Kekua, had died of cancer.
"You stuck to the script. And you knew that something was amiss, Manti," Couric said.
"Katie, put yourself in my situation. I, my whole world told me she died on Sept. 12. Everybody knew that. This girl, who I committed myself to, died on Sept. 12," said Te'o, who finished second in the voting for the 2012 Heisman Trophy.
Te'o's father, Brian, who joined the interview along with his wife, tearfully defended his son.
"People can speculate about what they think he is," Brian Te'o said. "I've known him 21 years of his life, And he's not a liar. He's a kid."
Diane O'Meara, the young woman whose photographs were used in the fake Twitter account of Te'o's online girlfriend said she knew nothing about the creation of Lennay Kekua.
"I've never met Manti Te'o in my entire life," she said on NBC's "Today" show Tuesday. "I've never spoken with him. I've never exchanged words with him."
She said she had received an apology from Ronaiah Tuiasosopo, 22, a former high school acquaintance who used her pictures, the day the hoax story broke on Deadspin.com.
Tuiasosopo has not publicly admitted involvement in the hoax.