The father of US terror suspect Ahmad Khan Rahami called law enforcement in 2014 to say his son was a “terrorist”, US officials have told the BBC.
Mohammad Rahami alerted authorities after a domestic dispute, expressing concern his son was an extremist before retracting the claim.
Mr Rahami said that the FBI determined his son was not a terror threat.
He is now suspected of “an act of terror” in Saturday’s blasts in New Jersey and New York, say prosecutors.
Mohammad Rahami first made the statement about his son as a terrorist to New Jersey police after the younger man was arrested and accused of stabbing his brother in 2014.
The information was provided to the FBI Joint Terrorism Task Force in Newark, New Jersey.
“Two years ago I go to the FBI because my son was doing really bad, OK?” Mr Rahami Snr told the New York Times.
“But they check almost two months, they say, ‘He’s OK, he’s clean, he’s not a terrorist.'”
“Now they say he is a terrorist. I say OK,” he told the newspaper.
The FBI reportedly launched an assessment, but Mohammad Rahami later withdrew his statement.
He said he only meant his son was spending time with criminals, a law enforcement official told the AP.
Authorities also determined Ahmad Khan Rahami had no ties to terrorist organisations, the official said.
A Justice Department official told the BBC they are going to “look into this further and see if there are any lessons to be learned”.
Though Mr Rahami was not on any terror watch lists, authorities are looking into whether he was radicalised on previous trips to Pakistan and Afghanistan.
He reportedly passed screening tests each time he returned from abroad, two US officials told Reuters.
Mr Rahami was arrested on Monday after Harinder Bains, an Indian immigrant businessman, found him napping in his pub doorway in Elizabeth, New Jersey.
He told CNN he initially thought the 28-year-old most-wanted suspect appeared “fatigued” and “exhausted”.
After watching television news from another business across the street, Mr Bains recognised Mr Rahami’s face in coverage of the manhunt for the bomber and alerted authorities.
Police confronted the suspect, who pulled a handgun and shot one of them. Mr Rahami was subsequently arrested after a gun battle with police.
The Afghan-born US citizen is charged with five counts of attempted murder of a law enforcement officer stemming from the shootout.
Police say they also have evidence linking him to the bomb in New York, which injured 29, and the explosion in New Jersey, which hurt no one.
The suspect – who lived with his Muslim family above their fried-chicken restaurant in Elizabeth – is being held on $5.2m bail after undergoing surgery for a gunshot wound to his leg.
Authorities have said no other suspects are at large.