A 58-year-old American man has been charged with mischief after a “mock” explosive device found in a suitcase set off a major investigation at Toronto Pearson International Airport.

The investigation held up a Chicago-bound United Airlines flight for hours, causing many passengers to miss their connecting flights in the U.S.

A U.S. Customs and Border Protection spokesperson said customs agents discovered “a mock improvised explosive device (IED) during an inspection of a traveller’s suitcase” at the airport’s pre-clearance area Thursday morning.

“CBP officers immediately notified Canadian Air Transport Security Authority (CATSA) who swabbed the mock IED for explosives with a negative result,” the spokesperson said in a statement.

“For the safety of travellers within the pre-clearance facility (PCF), CBP stopped all traveller processing while the mock IED was tested.”

Peel Regional Police said their explosive disposal unit examined the device and determined it was not an explosive.

Police identified the man charged in the incident as Joseph Galaska. He is being held in custody pending a bail hearing in a Brampton, Ont., courtroom.

After waiting for several hours on the tarmac, all passengers on United Flight 547 were escorted off the plane and re-screened in the airport’s isolation area.

The flight, which was scheduled to take off at 7 a.m., had its pre-clearance privileges revoked by U.S. Customs and Border Protection, according to an announcement made by the pilot.

The announcement was made as passenger Tory Galick spoke to CTV News Channel from the plane. At that point, the plane had been holding on the tarmac for nearly three hours.

Galick said passengers were initially told the delay was due to weather conditions in Chicago. But they later learned that a security issue was keeping the plane grounded.

As Galick explained the situation, the pilot could be heard addressing passengers over the plane’s intercom.

“Throughout my career, I have always been very truthful and honest about situations like these, and I’m going to just do that right now,” the pilot was heard saying. “The U.S. Customs has revoked the pre-clearance privileges for you to enter the United States. Therefore, we cannot leave at this time.”

Before the announcement was made, Galick said he saw a flight attendant approach one of the passengers on board and tell him that his bag had been flagged by U.S. customs. That person and a second passenger were then escorted off the plane, Galick said.

Throughout the incident, Toronto Pearson Airport said it was operating as normal.

Transportation Minister Marc Garneau said the government will be launching an inquiry to examine how well the incident was handled.