"He had numerous parts of an explosive device, except the explosive itself," said Ian Lafrenière of Montreal police.
Police searched the man's home in the city's LaSalle borough, trying to find clues in connection with a suspicious package that caused panic and delays at the airport for part of Sunday.
Several homes were evacuated and about 20 residents were displaced as the search was conducted.
Lafrenière said no explosive devices were found at the man's home, however, police recovered documents that they hope will provide answers.
“We have a lot of questions but not a lot of answers."
The incident began when the man's carry-on luggage was flagged in the U.S. customs area Sunday at around 5:45 a.m. ET by an airport employee.
A spokesperson for the airport said a police tactical team set up a large security perimeter near the terminal at 10:35 a.m. so officers could analyze the package, which was removed at about 1 p.m. The contents were sent to a lab for tests.
"We didn't want to take any risk and any chances, because when there's an airport, there's a lot of people, so that's why we evacuated certain parts," said Const. Jean-Pierre Brabant, a Montreal police spokesman.
The man, who is known to police, was taken into custody at the airport.
Lafrenière said everyone on the plane was searched, thinking the man may have been working with an accomplice.
However, Lafrenière said police have no reason to suspect anyone else is involved.
The man has not been charged, but is being questioned by police
"This is still a mystery for us. Why was he doing that?" said Lafrenière.