Plane diverted

(CNN) -- An American Airlines flight bound for London was diverted to New York's John F. Kennedy Airport early Thursday after a crew member uncovered a possible security breach, an airline spokeswoman said.

According to Sonja Whitemon, a crew member aboard Flight 136 -- scheduled to travel non-stop from Los Angeles International Airport to London Heathrow Airport -- questioned a passenger who the employee saw bypassing security by traveling on an employee-only bus from a parking lot to the LAX airport.

Following that conversation the decision to divert the Boeing 777 was made, Whitemon said.

The plane landed in New York at about 2:30 a.m. ET.

Meanwhile, Homeland Security Secretary Michael Chertoff told CNN's "American Morning" an initial report he received indicated the passenger in question was actually an employee traveling in a private capacity.

"I think they're still in the process of sorting this out," he said of airport officials. "It may very well turn out that this is nothing more than a misunderstanding with an employee who used an employee bus to get on a plane for a private flight." (Posted 7:02 a.m.)