Manti Te'o previously told reporters he and his girlfriend would spend hours speaking on the phone.
Notre Dame said it hired an independent investigative firm to look into the situation.
Swarbrick said the independent investigation found that the perpetrators were involved in "online chatter" indicating that it was a hoax, and Te'o was a victim.
"I will refer you to the documentary 'Catfish,'" the athletic director said.
"Catfish" is no longer simply a river dweller, but rather a verb defined as "to pretend to be someone you're not online by posting false information, such as someone else's pictures, on social media sites usually with the intention of getting someone to fall in love with you," according to an MTV show of the same name.
Swarbrick said he met with Te'o's family two days before Notre Dame played in the January 7 championship game and lost to Alabama. The linebacker is expected to be a first-round pick in the NFL draft this spring.