Suspected Chelsea bomber Ahmad Khan Rahami was reported to the FBI as a potential terrorist two years ago.
The New York Times reports his own father turned Rahami in, prompting an investigation by the FBI.
Mohammed told reporters: “I called the FBI two years ago.”
He was asked: “What did you tell them?”
He replied: “I told them, 'You got a connection with this guy'.’”
Mohammed told the Today show he knew nothing of the bombings.
He was asked: “Did you know that your son was doing this?”
“No,” he replied and continued to express that he had “no idea.”
He was then asked: “When you hear now that he has been accused of this do you believe it?”
“I am not sure what is going on,” the father answered.
Rahami, 28, attended Edison High School in New Jersey. He went to the prom with his girlfriend, Maria, whose last name has not been revealed to protect her anonymity. She is also the mother of his child.
Photos show Rahami and Maria with other classmates at the prom and frolicking with friends in the pool.
Maria told The New York Times: "My heart is just broken. I don't even know what to think." She's now accusing him of being a deadbeat dad.
Radio DJ Chris Konya was a classmate of Rahami, "To go from the kid at prom who could have ended up in a cubicle, selling cars or doing someone's taxes, to nine years later wanting to hurt people is just shocking."
Rahami has been charged with five counts of attempted murder of a law enforcement officer and two gun charges. His bail has been set at $5.2 million.