Massachusetts state police say they are working with various federal agents who are questioning a United Airlines passenger over a vehicle he left behind at the airport in Newark, N.J., that was initially reported to have contained explosives.

Police say an examination of the car's contents and questioning of the passenger on Saturday showed that the vehicle at Newark International Airport did not contain explosive materials.

Police identified the man as a salesperson for robot maker iRobot Corp. He is believed to have used items in his car as part of a sales demonstration.

Still, police say authorities continue to investigate the matter and declined to provide additional information.

Authorities did not identify the man because he has not been charged with a crime.

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