Federal US officials are attempting to determine how a stun gun was brought onboard a JetBlue flight that landed at Newark airport in New Jersey.Crew members at Liberty International Airport found the stun gun tucked into the back of a seat on the plane following the flight from Boston.
The FBI said on Monday that there was no indication the gun, found on Friday, was intended for an attack.
The gun was handed over to the Transportation Security Administration.
Members of the airline's crew were cleaning the JetBlue aircraft at 2220 local time (0220 GMT) on Friday evening when the gun was discovered.
FBI spokesman Bryan Travers said on Monday it was not clear who may have brought the stun gun on Flight 1179.
"People get caught bringing stuff to the checkpoint all the time," he said.
Authorities said they gave the weapon to the Port Authority of New York, before it was handed over to the Transportation Security Administration (TSA), the body responsible for carrying out security screening of passengers.
Port Authority spokesman Steve Coleman told the Newark Star-Ledger newspaper there was no indication the gun had been fired or how it was brought on the flight, which had carried 96 passengers from Boston to Newark.