An investigation is underway into why a young child, apparently under an adult's supervision, was allowed to direct air traffic at New York City's John F. Kennedy International Airport, U.S. authorities said Wednesday.

In transmissions broadcast by local media, the young child -- whose age is unknown -- can be heard directing pilots for departure, apparently under the supervision of an adult. The incident reportedly happened two weeks ago.

At one point an adult voice can be heard telling a pilot: "This is what you get guys when the kids are out of school."

The pilots receiving instructions from the child did not appear too concerned with one pilot saying "awesome job."

The Federal Aviation Administration (FAA) said that pending the outcome of its investigation the employees involved in the incident were not controlling air traffic.

"This behaviour is not acceptable and does not demonstrate the kind of professionalism expected from all FAA employees," the FAA said in a statement.

Nearly 48 million passengers pass through John F. Kennedy airport annually.